SYNTHESIS, STRUCTURE AND CATALYTIC APPLICATION OF NOVEL CARBENE COMPLEXES WITH BENZOTHIAZOLIN 2 YLIDENE LIGANDS 3

Chapter Three: Experimental

Experimental

Chapter Three
Experimental
3.1 Experimental
This Chapter contains all the general procedures of all the chemical syntheses,
Mizoroki-Heck reaction and Suzuki-Miyaura reaction.

3. 1. 1 General Procedures
Unless otherwise stated, all manipulations were performed under normal
laboratory conditions. All solvents and chemicals reagents were used as received.
Benzothiazole was purchased from Sigma-Aldrich Chemical Company and distilled
prior

to

use.

Pd(OAc)2,

triphenylphosphine,

tricyclohexylphosphine,

2-

diphenylphosphanylpyridine, pyrazine, trans-1,2-bis(4-pyridyl)ethylene, 1,2- bis(4pyridyl)ethane, 4,4’-bypyridine, 2-iodo-propane, 2-aminopyridine, 3-iodopyridine, 4tert-butyl-pyridine, imidazole, benzimidazole, benzooxazole, AgO2CCF3, Ag2O,
Ag2CO3, AgOAc, KOBut and 2-phenylpyridine were purchased from Sigma-Aldrich
and

used

as

received.

1,3-Dibenzylbenzimidazolium

bromide284

and

[Pt(C^N)(acac)]285 were prepared according to the literature.
1

H, 13C{1H}, 31P{1H},

195

Pt{1H} and 19F{1H} NMR spectra were recorded on

Bruker ACF 300 and Bruker AMX500 spectrometers using Me4Si (internal), 85%
H3PO4 (31P) (external), 1.2 M K2PtCl4 in D2O (195Pt -1620 ppm) (external) and
CF3CO2H (19F) (external) as standards respectively. ESI and FAB mass spectra were
obtained using a Finnigan LCQ. The yields of C-C coupling products were

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Experimental

determined by using a Finnigan/MAT 95XL-T spectrometer. Elemental analyses were
performed on a Perkin-Elmer PE 2400 elemental analyzer at the Department of
Chemistry, National University of Singapore.
For X-ray diffraction studies, suitable crystals were mounted on quartz fibers
and X-ray data collected on a Bruker AXS APEX diffractometer, equipped with a
CCD detector, using graphite-monochromated MoKα radiation (λ = 0.71073 Å). The
data collection, indexing and lattice parameter determination and polarization effects
were performed with the SMART suite programs.286 The integration of intensity of
reflections and scaling was performed by SAINT. The empirical absorption correction
was performed by SADABS.287 The space group determination, structure solution and
least-squares refinements on |F|2 were carried out with the SHELXTL.288 The
structures were solved by direct methods to locate the heavy atoms, followed by
difference maps for the light non-hydrogen atoms. Anisotropic thermal parameters
were refined for the rest of the non-hydrogen atoms. The hydrogen atoms were placed
in their ideal positions. The crystals of complexes 2.21, 2.22, 2.34(a) and 2.40 contain
two independent molecules in the asymmetric unit of the cell. The two terminal
carbon atoms of the propyl substituents of both molecules of C are disordered into
two positions of occupancy ratio 55/45. The hydrogen atoms of complex 2.6 were
refined to their coordinates shown. The three cyclohexyl rings of complex 2.10(a)
have relatively high thermal parameters and one of them is disordered into two
positions at a 50:50 ratio.

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Experimental

3.2 Synthesis of A-D and complexes 2.1-2.44

3.2.1 Synthesis of A-D (Chapter Two, Section 2.2)

3-Benzylbenzothiazolium bromide, A
A mixture of benzothiazole (3.71 g, 27.50 mmol) and benzyl bromide (4.70 g, 27.50
mmol) was stirred at 60 °C overnight. The off-white solid thus obtained was washed
several times with Et2O. Diffusion of Et2O into a concentrated CH2Cl2 solution
yielded transparent crystals suitable for X-ray diffraction studies. Yield: 8.34 g (27.23
mmol, 99%). 1H NMR (300 MHz, CDCl3): δ 12.27 (s, 1H, NCH), 8.30 (d, 3JHH = 8.0
Hz, 1H, Ar-H), 8.08 (d, 3JHH = 8.43 Hz, 1H, Ar-H), 7.76 (m, 2H, Ar-H), 7.53 (m, 2H,
Ar-H), 7.34 (m, 3H, Ar-H), 6.42 (s, 2H, CH2). 13C{1H} NMR (75.5 MHz, CDCl3): δ
165.1 (NCH), 140.1, 131.5, 131.3, 130.0, 129.5, 129.4, 129.0, 128.3, 124.8, 117.2
(Ar-C), 56.7 (CH2). MS (ESI, positive mode) m/z (%): 226 (100) [M - Br]+. Anal.
Calc. for C14H12BrNS (M = 306.22): C, 54.91; H, 3.95; N, 4.57; S, 10.47. Found: C,
54.72; H, 3.73; N, 4.48; S, 10.46.

3-(2-Propenyl)benzothiazolium bromide, B
Compound B was prepared using a similar procedure to A from benzothiazole (3.71 g,
27.50 mmol) and allyl bromide (3.33 g, 27.50 mmol). The solid thus obtained was
washed several times with Et2O. Diffusion of Et2O into a concentrated CH2Cl2
solution yielded transparent crystals suitable for X-ray diffraction studies. Yield: 5.71
g (22.30 mmol, 81%). 1H NMR (300 MHz, CDCl3): δ 11.87 (s, 1H, NCH) (in D2O,

this signal appears at 10.37 ppm),13 8.45 (d, 1H, 3JHH = 7.7 Hz, Ar–H), 8.14 (d, 1H,

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3

Experimental

JHH = 8.2 Hz, Ar–H), 7.82 (t, 1H, 3JHH = 7.8 Hz, Ar–H), 7.74 (t, 1H, 3JHH = 7.3 Hz,

Ar–H), 6.14 (m, 1H, CH2CH=CH2), 5.83 (d, 2H, 3JHH = 6.1 Hz, CH2CHCH2), 5.55 (d,
1H, 3JHH = 17.1 Hz, CH2CH=CHHtrans), 5.46 (d, 1H, 3JHH = 10.4 Hz, CH2CH=CHHcis).
C{1H} NMR (75.5 MHz, CDCl3): δ 165.0 (NCS), 140.1, 131.3 (Ar–C), 130.0

13

(CH2CH=CH2), 128.9, 128.8, 125.3, 123.0 (Ar–C), 117.1 (CH2CH=CH2), 55.4
(NCH2). MS (ESI, positive mode) m/z (%): 176 (100) [M − Br]+. Anal. Calc. for
C10H10BrNS (M = 256.16): C, 46.89; H, 3.93; N, 5.47; S, 12.52. Found: C, 46.48; H,
3.47; N, 5.32; S, 12.46.

3-Propylbenzothiazolium bromide, C
Compound C was prepared in using a similar procedure to A from benzothiazole
(3.71 g, 27.50 mmol) and 1-bromopropane (3.38 g, 27.50 mmol) at 120 °C. The
orange solid thus obtained was washed several times with Et2O. The solid was

continuously washed with ethyl acetate until a yellow solid was obtained. Diffusion of
Et2O into a concentrated CH2Cl2 solution yielded transparent crystals suitable for Xray diffraction studies. Yield: 5.55 g (21.50 mmol, 78%). 1H NMR (500 MHz, CDCl3):

δ 12.09 (s, 1H, NCH), 8.43 (d, 3JHH = 8.2 Hz, 1H, Ar–H), 8.11 (d, 3JHH = 8.9 Hz, 1H,
Ar–H), 7.89 (t, 1H, Ar–H), 7.80 (t, 1H, Ar–H), 5.12 (t, 2H, 3JHH = 7.3 Hz,
CH2CH2CH3), 2.17 (pseudo sext, 2H, CH2CH2CH3), 1.08 (t, 3H,
Hz,CH2CH2CH3).

3

JHH =7.3

C{1H} NMR (125MHz,CDCl3): δ 164.9 (NCH), 140.2, 131.4,

13

130.2, 129.1, 125.3, 116.5 (Ar–C), 54.7 (CH2CH2CH3), 22.9 (CH2CH2CH3), 0.9
(CH2CH2CH3). MS (ESI, positive mode) m/z (%): 178 (100) [M − Br]+. Anal. Calc.
for C10H12BrNS (M = 258.18): C, 46.52; H, 4.68; N, 5.43; S, 12.42. Found: C, 46.18;
H, 4.76; N, 5.51; S, 12.81.

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Experimental

3-Isopropylbenzothiazolium triiodide, D
D was prepared similarly to A from benzothiazole (3.74 g, 27.65 mmol) and 2-iodopropane (15.33 g, 90.16 mmol) at 100 °C for 2 days. The brown oil thus obtained was
washed several times with ethyl acetate to afford yellow solid. Diffusion of Et2O into
a concentrated CH2Cl2 solution yielded transparent crystals suitable for X-ray
diffraction studies. Yield: 4.91 g ( 8.78 mmol, 32%). 1H NMR (500 MHz, CDCl3): δ
11.52 (s, 1H, NCHS), 8.54 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 8.24 (d, 3JHH = 8.8 Hz, 1H,
Ar-H), 7.90 (t, 3JHH = 7.90Hz, 1H, Ar-H), 7.80 (t, 3JHH = 7.9 Hz, 1H, Ar-H), 5.51 (m,
3

JHH = 6.6 Hz, 1H, CH(CH3)2), 1.93 (d, 3JHH = 6.9 Hz, 6H, CH(CH3)2). 13C{1H} NMR

(125 MHz, CDCl3): δ 163.1 (s, NCHS), 140.1, 131.6, 130.3, 129.2, 125.8, 117.1 (s,
Ar-C), 57.4 (s, CH(CH3)2), 23.6 (s, CH(CH3)2). MS (ESI, positive mode) m/z (%):
178 (100) [M - I3]+. Anal. Calc. for C10H12BrNS (M = 558.99): C, 21.49; H, 2.16; N,
2.51; S, 5.74. Found: C, 21.81; H, 2.16; N, 2.54; S, 5.12.

3.2.2 Synthesis of Complexes 2.1-2.4 (Chapter Two, Section 2.3)

cis-Dibromobis(3-benzylbenzothiazolin-2-ylidene)palladium(II), 2.1
A mixture of A (306 mg, 1 mmol) and Pd(OAc)2 (112 mg, 0.5 mmol) was suspended
in CH3CN (30 mL) and refluxed overnight. The orange precipitate thus obtained was
washed several times with Et2O and water. Crystallization from CH2Cl2/Et2O gave
yellow crystalline needles suitable for X-ray diffraction. Yield: 326 mg (0.45 mmol,
91%). 1H NMR (500 MHz, DMSO-d6): δ 8.12 (d, 3JHH = 7.55 Hz, 2H, Ar-H), 7.537.25 (m, 16H, Ar-H), 6.38 (br s, 4H, CH2). 13C{1H} NMR (125 MHz, DMSO-d6): δ
203.8 (NCH), 142.5, 135.4, 134.6, 129.1, 128.9, 127.7, 127.4, 126.0, 123.2, 116.3
(Ar-C), 58.7 (CH2). MS (ESI, positive mode) m/z (%): 637 (100) [M - Br]+. Anal.
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Calc. for C28H22Br2N2PdS2 (M = 716.84): C, 46.92; H, 3.09; N, 3.91; S, 8.94. Found:
C, 45.75; H, 3.20; N, 3.97; S, 8.51. Repeated purification steps did not give
satisfactory analytical data for 2.1. It was prone to solvate (and H2O) entrapment.

Dibromo(µ-dibromo)bis(3-benzylbenzothiazolin-2-ylidene)-dipalladium(II), 2.2(a)
A mixture of A (306 mg, 1 mmol) and Pd(OAc)2 (112 mg, 0.5 mmol) was suspended
in DMSO (5 mL) and heated at 70 °C overnight. The solvent was removed under
vacuum, and CHCl3 (10 mL) was added. The mixture was left to stand for 2 days. The
orange solid thus obtained was filtered, washed with small amounts of CHCl3 and
Et2O, and dried under vacuum. X-ray-quality crystals were obtained from a saturated
CHCl3 solution. Yield: 109 mg (0.11 mmol, 45%). 1H NMR (300.1 MHz, DMSO-d6):

δ 8.15 (br s, 2H, Ar-H), 7.70-7.29 (m, 16H, Ar-H), 6.50 (s, 4H, CH2). 13C{1H} NMR
(75.5 MHz, DMSO-d6): δ 142.2, 136.0, 134.3, 129.1, 128.7, 128.0, 127.5, 125.9,
123.1, 115.8 (Ar-C), 58.9 (CH2). The signal for the carbene carbon could not be
detected under the given conditions. MS (FAB) m/z (%): 903 (100) [M - Br]+. Anal.
Calc. for Pd2Br4(C14H9NS)2.CHCl3 (M = 1102.45): C, 31.59; H, 2.10; N, 2.54; S, 5.82.
Found: C, 31.59; H, 2.32; N, 2.76; S, 6.09.

trans-Dibromo(acetonitrile)(3-benzylbenzothiazolin-2-ylidene)palladium(II), 2.3
CH3CN (15 mL) was added to complex 2.2(a) (295 mg, 0.3 mmol) and the mixture
heated under reflux overnight. The clear yellow solution was cooled to ambient
temperature and the solvent evaporated under vacuum. Yellow cubic single crystals of
3 were obtained from diffusion of Et2O into a concentrated CH3CN solution upon
standing. Yield: 295 mg (0.55 mmol, 92%) was obtained. 1H NMR (300.1 MHz,

CDCl3): δ 7.80 (m, 1H, Ar-H), 7.50-7.34 (m, 8H, Ar-H), 6.46 (br s, 2H, CH2), 2.00 (s,
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3H, CH3CN). 13C{1H} NMR (75.5 MHz, CDCl3): δ 191.5 (NCS), 142.2, 136.4, 133.0,
129.2, 129.1, 128.8, 127.4, 127.2, 125.6, 121.9 (Ar-C), 115.1 (CH3CN), 59.7 (CH2),
1.78 (CH3CN). MS (FAB) m/z (%): 572 (18) [M + K]+. Anal. Calc. for
C16H14Br2N2PdS (M = 532.58): C, 36.08; H, 2.65; N, 5.26; S, 6.02. Found: C, 33.52;
H, 3.00; N, 5.33; S, 6.16. Repeated purification steps did not give satisfactory
analytical data for 2.3. It is susceptible to loss of the CH3CN ligand and subsequent
dimerization to form 2.2(a).217

trans-Dibromo(3-benzylbenzothiazolin-2-ylidene)(N,Ndimethylformamide)
palladium(II), 2.4
A solution of complex 2.2(a) (295 mg, 0.30 mmol) in DMF (15 mL) was heated at
80 °C overnight. The yellow solution thus obtained was cooled to ambient
temperature and filtered, and the solvent of the filtrate was removed under vacuum.
Diffusion of Et2O into a concentrated DMF solution afforded yellow cubic crystals of
5 suitable for X-ray diffraction studies. Yield: 288 mg (0.51 mmol, 85%) was
obtained. 1H NMR (300.1 MHz, CDCl3): δ 8.02 (s, 1H, CHO), 7.82 (d, 3JHH = 6.7 Hz,
2H, Ar-H), 7.52-7.30 (m, 7H, Ar-H), 6.51 (br s, 2H, CH2), 2.96 (s, 3H, CH3), 2.88 (s,
3H, CH3).

C{1H} NMR (75.5 MHz, CDCl3): δ 191.9 (NCS), 162.6 (CHO), 142.5,

13

136.4, 133.0, 129.3, 128.8, 127.5, 127.2, 125.6, 121.9, 115.2 (Ar-C), 59.9 (CH2), 36.5
(CH3), 31.5 (CH3). MS (FAB) m/z (%): 412 (40) [M - Br - DMF]+. Anal. Calc. for
C17H18Br2N2OPdS (M = 564.63): C, 36.16; H, 3.21; N, 4.96; S, 5.68. Found: C, 36.43;
H, 3.25; N, 5.15; S, 5.83.

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3.2.3 Synthesis of Complexes 2.5-2.8 (Chapter Two, Section 2.4)

cis-Dibromobis[3-(2-propenyl)benzothiazolin-2-ylidene]palladium(II), cis-2.5
A mixture of B (256 mg, 1 mmol) and Pd(OAc)2 (112 mg, 0.5 mmol) was suspended
in CH3CN (30 ml) and refluxed overnight. The white precipitate thus obtained was
washed several times with Et2O and water. Diffusion of Et2O into a DMF solution
yielded crystals suitable for X-ray diffraction studies. Yield: 99 mg (0.16 mmol, 32%).
1

H NMR (500 MHz, DMSO-d6): δ 8.13 (d, 2H, 3JHH = 8.2 Hz, Ar–H), 7.95 (d, 2H,

3

JHH = 8.2 Hz, Ar–H), 7.60 (t, 2H, 3JHH = 7.9 Hz, Ar–H), 7.52 (t, 2H, 3JHH = 7.6 Hz,

Ar–H), 6.28 (m, 2H, CH2CHCH2), 5.92 (broad d, 3JHH = 4.4 Hz, 4H, CH2CHCH2),
5.41 (broad d, 2H, 3JHH = 17.0 Hz, CH2CH=CHHtrans), 5.36 (broad d, 2H, 3JHH = 10.1
Hz, CH2CH=CHHcis).

C{1H}NMR(125 MHz, DMSO-d6): δ 203.0 (NCS), 142.7,

13

135.1 (Ar–C), 131.8 (CH2CH=CH2), 127.7, 126.1 (Ar–C), 123.2, 120.6 (Ar–C), 116.2
(CH2CH=CH2), 58.1 (NCH2). MS (ESI, positive mode) m/z (%): 537 (100) [M − Br]+.
Anal. Calc. for C20H18Br2N2PdS2 (M = 616.73): C, 38.95; H, 2.94, N, 4.54; S, 10.40.
Found: C, 38.49; H, 3.06; N, 4.45; S, 10.02.

trans-Dibromobis[3-(2-propenyl)benzothiazolin-2-ylidene)palladium(II),

trans-

2.5
Column chromatography on the filtrate of the above reaction (SiO2, ethyl acetate)
afforded trans-2.5 as an orange powder. Yield: 185 mg (0.30 mmol, 60%). 1H NMR
(500 MHz, DMSO-d6): δ 8.17–8.11 (m, 2H, Ar–H), 8.01–7.94 (m, 2H, Ar–H), 7.63–
7.53 (m, 4H, Ar–H), 6.27 (m, 2H, CH2CHCH2), 5.92–5.85 (broad m, 4H,
CH2CHCH2), 5.59 (d, 2H, 3JHH = 17.0 Hz, CH2CH=CHHtrans), 5.40 (d, 2H, 3JHH = 9.4
Hz, CH2CH=CHHcis).

C{1H} NMR (125 MHz, DMSO-d6): δ 212.2 (NCS), 142.6,

13

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135.1 (Ar–C), 131.7 (CH2CH=CH2), 127.7, 126.1 (Ar–C), 123.4, 120.6 (Ar–C), 116.2
(CH2CH=CH2), 58.3 (NCH2). MS (ESI, positive ions): m/z (%) 537 (100) [M − Br]+.
Anal. Calc. for C20H18Br2N2PdS2 (M = 616.73): C, 38.95; H, 2.94, N, 4.54; S, 10.40.
Found: C, 37.85; H, 3.39; N, 3.78; S, 9.17.

cis-Di(trifluoroacetato)bis[3-(2-propenyl)benzothiazolin-2-ylidene]palladium(II),
2.8
A mixture of complex cis-2.5 (308 mg, 0.5 mmol) and AgO2CCF3 (221 mg, 1 mmol)
was suspended in CH3CN (20 ml) and stirred at r.t. overnight shielded from light. The
resulting light yellow suspension was filtered from the precipitated AgBr over Celite
and the solvent removed in vacuum to give the crude product as a white powder. It
was washed several times with Et2O. Yield: 157 mg (0.23 mmol, 46%). 1H NMR(500
MHz, DMSO-d6): δ 8.19 (d, 2H, 3JHH = 7.6 Hz, Ar–H), 8.00 (d, 2H, 3JHH = 8.2 Hz,
Ar–H), 7.65 (t, 2H, 3JHH = 7.9 Hz, Ar–H), 7.57 (t, 2H, 3JHH = 7.6 Hz, Ar–H), 6.07 (m,
2H, CH2CH=CH2), 5.95 (d, 4H, 3JHH = 5.1 Hz, CH2CHCH2), 5.22 (d, 2H, 3JHH = 10.1
Hz, CH2CH=CHHcis), 5.16 (d, 2H, 3JHH = 17.6 Hz, CH2CH=CHHtrans). 13C{1H} NMR
(125 MHz, DMSO-d6): δ 192.0 (NCS), 159.0 (COO), 142.5, 135.1 (Ar–C), 131.7
(CH2CH=CH2), 128.1, 126.5, 123.6, 119.7 (Ar–C), 116.5 (CH2CH=CH2), 57.7
(NCH2). The signals for the CF3 could not be detected under the given conditions.
19

F{1H} NMR (282.38 MHz, DMSO-d6): δ 2.49 (s, CF3). MS (ESI, positive mode)

m/z (%): 487 (64) [M − 2O2CCF3 + OCH3]+. Anal. Calc. for C24H18F6N2O4PdS2 (M =
682.95): C, 42.21; H, 2.66; N, 4.10; S, 9.39. Found: C, 41.80; H, 2.38; N, 4.15; S,
9.46.

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3.2.4 Synthesis of Complexes 2.2(b) and 2.9-2.11 (Chapter Two,
Section 2.5)

Dibromo(µ-dibromo)bis(3-propylbenzothiazolin-2-ylidene)dipalladium(II), 2.2(b)
Complex 2.2(b) was prepared similarly to 2.2(a) from C (518 mg, 2 mmol) and
Pd(OAc)2 (225 mg, 1 mmol). Yield: 337 mg (0.38 mmol, 76%). 1H NMR (300 MHz,
DMSO-d6): δ

8.13 (br, m, 4H, Ar–H), 7.59 (m, 4H, Ar–H), 5.07 (br, t, 4H,

CH2CH2CH3), 2.17 (br, m, 4H, CH2CH2CH3), 1.08 (t, 6H,
CH2CH2CH3).

13

3

JHH = 6.0 Hz,

C{1H} NMR (75 MHz, DMSO-d6): δ 142.0, 135.2, 127.2, 125.4,

122.5, 114.8 (Ar–C), 54.8 (CH2CH2CH3), 21.4 (CH2CH2CH3), 11.07 (CH2CH2CH3).
MS (FAB, positive ions) m/z (%): 807 (10) [M − Br]+. Anal. Calc. C20H22Br4N2Pd2S2
(M = 886.98): C, 27.08; H, 2.50; N, 3.16; S, 7.23. Found: C, 26.27; H, 2.90;N, 3.05; S,
7.89.

cis-Dibromo(3-benzylbenzothiazolin-2-ylidene)(triphenylphosphine)Pd(II), 2.9(a)
A mixture of 2.2(a) (983 mg, 1 mmol) and PPh3 (525 mg, 2 mmol) was suspended in
CH2Cl2 (5 mL) and stirred overnight at r.t.. Et2O (15 mL) was added to give a yellow
precipitate which was filtered and washed with Et2O. Yield: 905 mg (1.20 mmol,
60%). 1H NMR (500 MHz, CDCl3): δ 7.71–7.70 (m, 1H, Ar–H), 7.63–7.59 (m, 7H,
Ar–H). 7.54–7.52 (m, 1H, Ar–H), 7.49–7.47 (m, 1H, Ar–H), 7.37–7.34 (m, 4H, Ar–
H), 7.31–7.28 (m, 1H, Ar–H), 7.25–7.22 (m, 8H, Ar–H), 7.16–7.15 (m, 1H, Ar–H),
6.53 (d, 1H, 2JHH = 15.1 Hz, NCHH), 5.00 (d, 1H, 2JHH = 15.1 Hz, NCHH).
P{1H}NMR(202.43 MHz, CDCl3): δ 27.3 (s, PPh3).

31

13

C{1H} NMR(125 MHz,

CDCl3): δ 208.4 (NCS), 167.8, 142.2, 136.5 (Ar–C), 134.5 (d, 2/3JCP = 10.90 Hz, Ar–
C), 132.6, 132.5 (Ar–C), 131.1 (d, 4JCP = 2.74 Hz, Ar–C), 130.8, 130.0, 129.6, 128.9

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(Ar–C), 128.8 (d, 4JCP = 2.73 Hz, Ar–C), 128.4 (d,

Experimental

2/3

JCP = 10.90 Hz, Ar–C), 128.2,

126.6, 125.07, 121.7, 115.2 (Ar–C), 59.5 (NCH2). MS (ESI, positive mode) m/z (%):
674 (100) [M − Br]+. Anal. Calc. for C32H26Br2NPPdS (M = 753.82): C, 50.99; H,
3.48; N, 1.86; S, 4.25. Found: C, 49.59; H, 3.32; N, 1.38; S, 4.56.

cis-Dibromo(3-propylbenzothiazolin-2-ylidene)(triphenylphosphine)Pd(II), 2.9(b)
Complex 2.9(b) was prepared similarly to 2.9(a) from 2.2(b) (887 mg, 1 mmol) and
PPh3 (525 mg, 2 mmol). Yield: 762 mg (1.08 mmol, 54%). 1H NMR (500 MHz,
CDCl3): δ 7.68–7.64 (m, 6H, Ar–H), 7.61 (d, 1H, 3JHH = 7.6 Hz, Ar–H). 7.43–7.41 (m,
1H, Ar–H), 7.36–7.32 (m, 5H, Ar–H), 7.25–7.22 (m, 6H, Ar–H), 4.81 (dt, 1H, 3JHH =
12.5 Hz, 2JHH = 5.4 Hz, CHHCH2CH3), 4.05 (dt, 1H, 3JHH = 12.5 Hz, 2JHH = 5.4 Hz,
CHHCH2CH3), 2.41 (m, 1H, CH2CHHCH3), 1.79 (m, 1H, CH2CHHCH3), 1.07 (t, 3H,
3

JHH = 7.6 Hz, CH2CH2CH3). 31P{1H} NMR (202.43 MHz, CDCl3): δ 27.7 (s, PPh3).
C{1H} NMR (125 MHz, CDCl3): δ 206.3 (NCS), 142.0, 136.4 (Ar–C), 134.3 (d,

13

2/3

JCP = 10.94 Hz, Ar–C), 131.1 (d, 4JCP = 2.74 Hz, Ar–C), 129.9, 129.5 (Ar–C), 128.3

(d,

2/3

JCP = 10.93 Hz, Ar–C), 126.7, 125.1, 121.9, 113.8 (Ar–C), 57.3 (CH2CH2CH3),

21.3 (CH2CH2CH3), 11.6 (CH2CH2CH3). MS (ESI, positive mode) m/z (%): 658 (100)
[M − Br + CH3OH]+. Anal. Calc. for C28H26Br2NPPdS (M = 705.78): C, 47.65; H,
3.71; N, 1.98; S, 4.54. Found: C, 47.06; H, 3.52; N, 1.79; S, 4.89.

cis-Dibromo(3-benzylbenzothiazolin-2-ylidene)(tricyclohexylphosphine)Pd(II),
2.10(a)
Complex 2.10(a) was prepared similarly to 2.9(a) from 2.2(a) (983 mg, 1 mmol) and
PCy3 (561 mg, 2 mmol). The yellow precipitate was obtained by filtration. Yield: 1.02
g (1.32 mmol, 66%). 1H NMR (500 MHz, CDCl3): δ 7.86 (d, 1H, 3JHH = 8.2 Hz, Ar–
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H), 7.44–7.31 (m, 8H, Ar–H), 6.69 (d, 2H, 2JHH = 15.8 Hz, NCHH), 6.14 (d, 2H, 2JHH
= 15.8 Hz, NCHH), 2.25–2.12 (m, 6H, CH2), 1.80 (broad s, 7H, CH2), 1.66–1.58 (m,
10H, CH2), 1.25–1.12 (m, 7H, CH2), 0.91 (br, s, 3H, PCH).
MHz, CDCl3): δ 44.7 (s, PCy3).

13

31

P{1H} NMR (202.43

C{1H} NMR (125 MHz, CDCl3): δ 208.7 (NCS),

142.8, 135.6, 132.8, 128.8, 128.4, 127.6, 127.1, 125.6, 122.0, 115.8 (Ar–C), 61.1
(NCH2), 36.6 (d, 1JCP = 21.9 Hz, PCH), 30.5, 29.8 (CH2), 27.5 (d,

2/3

JCP = 10.9 Hz,

CH2), 26.0 (CH2). MS (ESI, positive mode) m/z (%): 692 (100) [M − Br]+. Anal. Calc.
for C32H44Br2NPPdS (M= 771.97): C, 49.79; H, 5.74; N, 1.81; S, 4.15. Found: C,
49.37; H, 5.78; N, 1.89; S, 3.95.

cis-Dibromo(3-propylbenzothiazolin-2-ylidene)(tricyclohexylphosphine)Pd(II),
2.10(b)
Complex 2.10(b) was prepared similarly to 2.9(a) from 2.2(b) (887 mg, 1 mmol) and
PCy3 (561 mg, 2 mmol). The yellow precipitate was obtained and filtered. Yield: 1.01
g (1.40 mmol, 70%). 1H NMR (500 MHz, CDCl3): δ 7.86 (d, 1H, 3JHH = 8.2 Hz, Ar–

H), 7.66 (d, 1H, 3JHH = 8.9 Hz, Ar–H), 7.57 (t, 1H, 3JHH = 7.7 Hz, Ar–H), 7.49 (t, 1H,
3

JHH = 7.6 Hz, Ar–H), 5.39 (dt, 1H, 2JHH = 12.5, 3JHH =4.6 Hz, CHHCH2CH3), 4.46

(dt, 1H, 2JHH =12.5, 3JHH = 4.6 Hz, CHHCH2CH3), 2.72 (m, 1H, CH2CHHCH3), 1.95
(m, 1H, CH2CHHCH3), 2.19 (br s, 7H, CH2), 1.80–1.62 (m, 23H, CH2), 1.16 (t, 3H,
3

JHH = 7.3 Hz, CH2CH2CH3), 0.86–0.83 (m, 3H, PCH). 31P{1H} NMR (202.43 MHz,

CDCl3): δ 43.7 (s, PCy3).

13

C{1H} NMR (125 MHz, CDCl3): δ 206.0 (NCS), 142.3,

135.8, 127.2, 125.6, 122.3, 114.2 (Ar–C), 59.1 (CH2CH2CH3), 36.5 (d, 1JCP = 21.9 Hz,
PCH), 30.7, 29.6 (CH2), 27.6 (d, 2/3JCP = 8.2 Hz, CH2), 27.5 (d, 2/3JCP = 6.4 Hz, CH2),
26.9 (CH2), 20.7 (CH2CH2CH3), 11.7 (CH2CH2CH3). MS (ESI, positive mode) m/z
(%): 644 (100) [M − Br]+. Anal. Calc. for C28H44Br2NPPdS (M = 723.92): C, 46.46;
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H, 6.13; N, 1.93; S, 4.43. Found: C, 46.43; H, 6.35; N, 2.05; S, 4.31.

cis-Dibromo(3-benzylbenzothiazolin-2-ylidene)(2-diphenylphosphanylpyridine)Pd(II), 2.11(a)
Complex 2.11(a) was prepared similarly to 2.9(a) from 2.2(a) (983 mg, 1 mmol) and
PPh2Py (527 mg, 2 mmol). The white precipitate obtained was filtered and washed
with Et2O. Yield: 906 mg (1.20 mmol, 60%). 1H NMR (500 MHz, CDCl3): δ 8.20 (d,
1H, 3JHH = 5.1 Hz, Ar–H), 7.97–7.93 (m, 2H, Ar–H), 7.73–7.69 (m, 2H, Ar–H), 7.60–
7.57 (m, 3H, Ar–H), 7.51–7.49 (m, 2H, Ar–H), 7.47–7.40 (m, 1H, Ar–H), 7.36–7.32
(m, 2H, Ar–H), 7.31–7.20 (m, 8H, Ar–H), 7.15–7.13 (m, 1H, Ar–H), 7.10–7.07 (m,
1H, Ar–H), 6.78 (d, 1H, 2JHH = 15.5 Hz, NCHH), 5.26 (d, 1H, 2JHH = 15.5 Hz,
NCHH).

31

P{1H} NMR (202.43 MHz, CDCl3): δ 24.5 (s, PPh2Py).

13

C{1H} NMR

(125 MHz, CDCl3): δ 207.7 (NCS), 156.0, 155.4 (Ar–C), 149.5 (d, 1/2JCP = 16.4 Hz,
Ar–C), 142.2, 136.5 (Ar–C), 135.99 (d, 3JCP =8.2 Hz, Ar–C), 135.93 (d,
Hz, Ar–C), 135.8 (Ar–C), 134.2 (d,

2/3

2/3

JCP =10.9

JCP = 10.9 Hz, Ar–C), 133.0, 131.5 (Ar–C),

131.0 (d, 4JCP =2.7 Hz, Ar–C), 130.5, 130.3, 130.2, 129.8, 128.9, 128.8, 128.5, 128.4
(Ar–C), 128.2 (d,

2/3

JCP = 10.9 Hz, Ar–C), 127.9, 126.5, 124.9 (Ar–C), 124.1 (d, 4JCP

= 2.7 Hz, Ar–C), 121.6, 115.3 (Ar–C), 60.2 (NCH2). MS (ESI, positive mode) m/z
(%): 675 (100) [M − Br]+. Anal. Calc. for C31H25Br2N2PPdS (M = 754.81): C, 49.33;
H, 3.34; N, 3.71; S, 4.25. Found: C, 48.93; H, 3.11; N, 3.63; S, 3.98.

cis-Dibromo(3-propylbenzothiazolin-2-ylidene)(2-diphenylphosphanylpyridine)Pd(II), 2.11(b)
Complex 2.11(b) was prepared similarly to 2.9(a) from 2.2(b) (887 mg, 1 mmol) and
PPh2Py (527 mg, 2 mmol). The white precipitate obtained was filtered and washed
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with Et2O. Yield: 1.02 g (1.44 mmol, 72%). 1H NMR (500 MHz, CDCl3): δ 8.23 (d,
1H, 3JHH = 4.4 Hz, Ar–H), 7.97–7.92 (m, 2H, Ar–H), 7.75–7.70 (m, 2H, Ar–H), 7.61–
7.55 (m, 3H, Ar–H), 7.45–7.39 (m, 3H, Ar–H), 7.36–7.32 (m, 3H, Ar–H), 7.27–7.25
(m, 1H, Ar–H), 7.22–7.19 (m, 2H, Ar–H), 7.10–7.07 (m, 1H, Ar–H), 5.04 (dt, 1H,
2

JHH = 12.6 Hz, 3JHH = 4.9 Hz, CHHCH2CH3), 4.28 (dt, 1H, 2JHH = 12.6 Hz, 3JHH =

4.9 Hz, CHHCH2CH3), 2.39 (m, 1H, CH2CHHCH3), 1.88 (m, 1H, CH2CHHCH3),
1.07 (t, 3H, 3JHH = 7.3 Hz, CH2CH2CH3).
24.6 (s, PPh2Py).

13

(Ar–C), 149.50 (d,

31

P{1H} NMR (202.43 MHz, CDCl3): δ

C{1H} NMR (125 MHz, CDCl3): δ 205.3 (NCS), 156.0, 155.3

1/2

JCP = 17.3 Hz, Ar–C), 142.0, 136.2 (Ar–C), 135.9 (d, 3JCP = 9.6

Hz, Ar–C), 134.2 (d, 2/3JCP = 10.0 Hz, Ar–C), 131.5 (d, 4JCP = 1.8 Hz, Ar–C), 131.0 (d,
4

JCP = 1.8 Hz, Ar–C), 130.5, 130.3, 130.2, 129.8, 128.8 (Ar–C), 128.4 (d, 2/3JCP = 11.9

Hz, Ar–C), 128.1 (d,

2/3

JCP = 10.9 Hz, Ar–C), 126.6, 124.9 (Ar–C), 124.1 (d, 4JCP =

2.7 Hz, Ar–C), 121.8, 113.9 (Ar–C), 57.4 (CH2CH2CH3), 21.2 (CH2CH2CH3), 11.5
(CH2CH2CH3). MS (ESI, positive mode) m/z (%): 627 (100) [M − Br]+. Anal. Calc.
for C27H25Br2N2PPdS (M = 706.77): C, 45.88; H, 3.57; N, 3.96; S, 4.54. Found: C,
45.32; H, 3.52; N, 4.01; S, 4.35.

3.2.5 Synthesis of Complexes 2.12-2.16 (Chapter Two, Section 2.6)

trans-Dibromo(3-benzylbenzothiazolin-2-ylidene)(pyridine)palladium(II), 2.12(a)
Pyridine (5 mL) was added to complex 2.2(a) (60 mg, 0.06 mmol) and the mixture
was stirred at r.t. for overnight. The clear yellow solution was evaporated under
vacuum. The yellow solid was dissolved in CH2Cl2 and Et2O was added to induce
precipitation. The product was washed with Et2O and dried. Diffusion of Et2O into a
sample solution in CH2Cl2 yielded yellow crystals suitable for X-ray diffraction
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studies. Yield: 68 mg (0.12 mmol, 98 %). 1H NMR (500 MHz, CDCl3): δ 9.01 (m,
2H, Ar-H), 7.81 (d, 3JHH = 8.9 Hz, 1H, Ar-H), 7.76 (tt, 3JHH = 1.6 Hz, 2JHH = 7.9 Hz,
1H, Ar-H), 7.57 (d, 3JHH = 6.9 Hz, 2H, Ar-H), 7.44 (d, 3JHH = 8.2 Hz, 1H, Ar-H),
7.40-7.31 (m, 7H, Ar-H), 6.54 (s, 2H, CH2);

C{1H} NMR (125 MHz, CDCl3): δ

13

195.7 (NCS), 162.7, 147.9, 142.8, 130.9, 129.6, 129.3, 129.1, 128.5, 128.2, 127.9,
127.6, 126.7, 125.1, 124.7, 124.5, 121.8, 115.1 (Ar-C), 60.1 (CH2); MS (ESI, positive
mode) m/z (%): 571 (100) [M + H]+. Anal. Calc. for C19H16Br2PdN2S.CH2Cl2.py (M =
734.67): C, 40.87; H, 3.16; N, 5.72; S, 4.36. Found: C, 40.99; H, 3.19; N, 5.72; S,
4.96.

trans-Dibromo(3-propylbenzothiazolin-2-ylidene)(pyridine)palladium(II), 2.12(b)
Complex 2.12(b) was prepared similarly to 2.12(a) from 2.2(b) (79 mg, 0.09 mmol).
Diffusion of Et2O into a solution in CH2Cl2 yielded yellow crystals suitable for X-ray
diffraction studies. Yield: 89 mg (0.17 mmol, 98%). 1H NMR (500 MHz, CDCl3): δ
9.04 (d, 3JHH = 6.4 Hz, 2H, Ar-H), 7.82 (d, 3JHH = 8.0 Hz, 1H, Ar-H), 7.79 (t, 3JHH =
7.6 Hz, 1H, Ar-H), 7.68 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 7.51 (t, 3JHH = 7.9 Hz, 1H, ArH), 7.42 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 7.37 (t, 3JHH = 6.9 Hz, 2H, Ar-H), 5.15 (t, 3JHH
= 8.2 Hz, 2H, CH2CH2CH3), 2.35 (m, 3JHH = 7.9 Hz, 2H, CH2CH2CH3), 1.22 (t, 3JHH
= 7.6 Hz, 3H, CH2CH2CH3);

C{1H} NMR (125 MHz, CDCl3): δ 193.3 (NSC),

13

154.4, 152.7, 149.8, 142.8, 138.1, 136.7, 126.7, 125.1, 124.7, 121.9, 113.8 (Ar-C),
56.9 (CH2CH2CH3), 22.7 (CH2CH2CH3), 11.7 (CH2CH2CH3); MS (ESI, positive
mode) m/z (%): 443 (40) [M - Br]+. Anal. Calc. for C15H16Br2N2PdS (M = 522.59): C,
34.47; H, 3.09; N, 5.36; S, 6.14. Found: C, 35.65; H, 2.98; N, 5.54; S, 6.09.

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Dibromo(µ-pyrazine)bis(3-benzylbenzothiazolin-2-ylidene)dipalladium(II),
2.13(a)
A mixture of 2.2(a) (122 mg, 0.12 mmol) and pyrazine (9.9 mg, 0.12 mmol) was
suspended in CH2Cl2 (5 mL) and stirred at r.t. for overnight. Et2O (15 mL) was added
to give a yellow precipitate which was collected from filtration. Diffusion of Et2O into
a CH2Cl2 solution yielded yellow crystals suitable for X-ray diffraction studies. Yield:
64 mg (0.06 mmol, 50 %). 1H NMR (500 MHz, CDCl3): δ 9.22 (s, 4H, Ar-H), 7.83 (d,
3

JHH = 7.6 Hz, 2H, Ar-H), 7.52 (d, 3JHH = 6.9 Hz, 4H, Ar-H), 7.46 (d, 3JHH = 8.2 Hz,

2H, Ar-H), 7.41-7.33 (m, 10H, Ar-H), 6.46 (s, 4H, CH2).

13

C{1H} NMR (125 MHz,

CDCl3): δ 191.8 (NSC), 148.4, 147.6, 146.9, 146.4, 142.7, 136.7, 133.2, 129.2, 128.7,
127.6, 126.9, 125.4, 121.8, 115.2 (Ar-C), 60.2 (CH2); MS (ESI) m/z (%): 1080 (30)
[M + Na]+. Anal. Calc. for C32H26Br4N4Pd2S2 (M = 1063.16): C, 36.15; H, 2.46; N,
5.27; S, 6.03. Found: C, 36.83; H, 2.76; N, 4.76; S, 6.25.

Dibromo(µ-pyrazine)bis(3-propylbenzothiazolin-2-ylidene)dipalladium(II),
2.13(b)

Complex 2.13(b) was prepared similarly to 2.13(a) from 2.2(b) (127 mg, 0.14 mmol)
and pyrazine (11.5 mg, 0.14 mmol). Yield: 68 mg (0.07 mmol, 50 %). 1H NMR (500
MHz, CDCl3): δ 9.30 (s, 4H, Ar-H), 7.85 (d, 3JHH = 8.2 Hz, 2H, Ar-H), 7.71 (d, 3JHH =
8.8 Hz, 2H, Ar-H), 7.55 (t, 3JHH = 7.9 Hz, 2H, Ar-H), 7.46 (t, 3JHH = 7.6 Hz, 2H, ArH), 5.10 (t, 3JHH = 8.2 Hz, 4H, CH2CH2CH3), 2.32 (m, 3JHH = 7.8, 4H, CH2CH2CH3),
1.22 (t, 3JHH = 7.6, 6H, CH2CH2CH3).

C{1H} NMR (125 MHz, CDCl3): δ 148.3,

13

146.9, 142.7, 136.6, 126.9, 125.3, 122.0, 113.9 (Ar-C), 57.2 (CH2CH2CH3), 21.9
(CH2CH2CH3), 11.6 (CH2CH2CH3); MS (ESI) m/z (%): 985 (10) [M - Br +

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3CH3OH]+. Anal. Calc. for C24H26Br4N4Pd2S2 (M = 967.08): C, 29.81; H, 2.71; N,
5.79; S, 6.63. Found: C, 29.92; H, 2.74; N, 5.53; S, 6.15.

Dibromo(µ-4,4’-bipyridine)bis(3-benzylbenzothiazolin-2-ylidene)dipalladium(II),
2.14(a)
Complex 2.14(a) was prepared similarly to 2.13(a) from 2.2(a) (122 mg, 0.12 mmol)
and 4, 4’-bipyridine (19 mg, 0.12 mmol). Yield: 86 mg (0.07 mmol, 60 %). 1H NMR
(500 MHz, DMSO-d6): δ 9.03 (s, 3H, Ar-H), 8.76 (s, 5H, Ar-H), 8.18-8.02 (m, 4H,

Ar-H), 7.89 (s, 2H, Ar-H), 7.75-7.51 (m, 8H, Ar-H), 7.37 (s, 4H, Ar-H), 6.63 (s, 4H,
CH2).

C{1H} NMR (125 MHz, DMSO-d6): δ 141.9, 134.9, 134.1, 128.6, 128.0,

13

127.1, 126.9, 125.5, 122.7, 115.8 (Ar-C), 58.2 (CH2). Anal. Calc. for
C38H30Br4N4Pd2S2.CH2Cl2 (M = 1224.19): C, 38.26; H, 2.63; N, 4.58; S, 5.24. Found:
C, 39.69; H, 2.46; N, 4.69; S, 5.39.

Dibromo(µ-4,4’-bipyridine)bis(3-propylbenzothiazolin-2-ylidene)dipalladium(II),
2.14(b)
Complex 2.14(b) was prepared similarly to 2.13(a) from 2.2(b) (100 mg, 0.11 mmol)
and 4, 4’-bipyridine (17.2 mg, 0.11 mmol). Yield: 63 mg (0.06 mmol, 55 %). 1H
NMR (500 MHz, DMSO-d6): δ 9.05 (m, 3H, Ar-H), 8.78 (s, 1H, Ar-H), 8.18 (m, 4H,
Ar-H), 8.07 (m, 3H, Ar-H), 7.89 (s, 1H, Ar-H), 7.66 (t, 3JHH = 6.9 Hz, 2H, Ar-H), 7.56
(t, 3JHH = 6.9 Hz, 2H, Ar-H), 5.21 (broad s, 4H, CH2CH2CH3), 2.25 (broad s, 4H,
CH2CH2CH3), 1.14 (broad s, 6H, CH2CH2CH3); MS (ESI) m/z (%): 964 (20) [M Br]+. Anal. Calc. for C30H30Br4N4Pd2S2 (M = 1043.17): C, 34.54; H, 2.90; N, 5.37; S,
6.15. Found: C, 34.90; H, 2.88; N, 5.31; S, 6.08.

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Dibromo[µ-trans-1,2-bis(4-pyridyl)ethylene]bis(3-benzylbenzothiazolin-2ylidene)dipalladium(II), 2.15(a)
Complex 2.15(a) was prepared similarly to 2.13(a) from 2.2(a) (215 mg, 0.22 mmol)
and trans-1,2-bis(4-pyridyl)ethylene (40 mg, 0.22 mmol). Yield: 210 mg (0.18 mmol,
82 %). 1H NMR (500 MHz, DMSO-d6): δ 8.90 (s, 4H, Ar-H), 8.17 (d, 3JHH = 8.2 Hz,
2H, Ar-H), 7.78 (s, 2H, CH=CH), 7.74-7.64 (m, 8H, Ar-H), 7.51-7.50 (m, 5H, Ar-H),
7.39-7.37 (m, 5H, Ar-H), 7.23 (s, 2H, Ar-H) 6.62 (s, 4H, CH2).

13

C{1H} NMR (125

MHz, DMSO-d6): δ 153.0, 142.5, 136.1, 134.8, 132.3 (Ar-C), 129.2, 128.7
(CH2=CH2), 128.5, 128.3, 127.6, 127.5, 127.4, 126.0, 125.9, 123.2, 123.0, 116.3,
115.9 (Ar-C), 59.0 (CH2). Anal. Calc. for C40H32Br4N4Pd2S2 (M = 1165.29): C, 41.23;
H, 2.77; N, 4.81; S, 5.50. Found: C, 40.06; H, 2.71; N, 4.99; S, 5.15.

Dibromo[µ-trans-1,2-bis(4-pyridyl)ethylene]bis(3-propylbenzothiazolin-2ylidene)dipalladium(II), 2.15(b)
Complex 2.15(b) was prepared similarly to 2.13(a) from 2.2(b) (218 mg, 0.24 mmol)
and trans-1,2-bis(4-pyridyl)ethylene (44 mg, 0.24 mmol). Yield: 184 mg (0.17 mmol,
70 %). 1H NMR (500 MHz, DMSO-d6): δ 8.91 (s, 4H, Ar-H), 8.17 (d, 3JHH = 7.6 Hz,
4H, Ar-H), 7.81 (s, 4H, Ar-H), 7.72 (s, 2H, CH=CH), 7.66 (t, 3JHH = 7.9 Hz, 2H, ArH), 7.56 (t, 3JHH = 7.9 Hz, 2H, Ar-H), 5.20 (t, 3JHH = 7.3 Hz, 4H, CH2CH2CH3), 2.24
(m, 3JHH = 7.4 Hz, 4H, CH2CH2CH3), 1.14 (t, 3JHH= 6.9 Hz, 6H, CH2CH2CH3). Anal.
Calc. for C32H32Br4N4Pd2S2 (M = 1069.21): C, 35.95; H, 3.02; N, 5.24; S, 6.00.
Found: C, 36.22; H, 2.84; N, 5.00; S, 6.06.

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Dibromo[µ-1,2-bis(4-pyridyl)ethane]bis(3-benzylbenzothiazolin-2ylidene)dipalladium(II), 2.16(a)
Complex 2.16(a) was prepared similarly to 2.13(a) from 2.2(a) (100 mg, 0.10 mmol)
and trans-1,2-bis(4-pyridyl)ethylene (18.7 mg, 0.10 mmol). Diffusion of CH2Cl2 into
a sample solution in DMSO yielded orange crystal suitable for X-ray diffraction
studies. Yield: 71 mg (0.06 mmol, 60 %). 1H NMR (500 MHz, CDCl3): δ 8.92 (d,
3

JHH = 6.3 Hz, 4H, Ar-H), 7.81 (d, 3JHH = 8.2 Hz, 2H, Ar-H), 7.71-7.69 (m, 2H, Ar-

H), 7.57 (d, 3JHH = 7.6 Hz, 2H, Ar-H), 7.54-7.52 (m, 2H, Ar-H), 7.44 (d, 3JHH = 8.2
Hz, 2H, Ar-H), 7.39-7.32 (m, 10H, Ar-H), 7.17 (d, 3JHH = 6.3 Hz, 2H, Ar-H), 6.53 (s,
4H, CH2), 2.93 (s, 4H, CH2CH2). 13C{1H} NMR (125 MHz, CDCl3): δ 195.8 (NSC),
167.8, 152.7, 151.8, 142.8, 136.8, 133.6, 132.5, 130.8, 129.1, 128.8, 128.5, 127.7,
126.7, 125.1, 124.5, 121.8, 115.1 (Ar-C), 60.1 (CH2), 38.8 (CH2CH2); MS (ESI) m/z
(%): 1088 (50) [M - Br]+. Anal. Calc. for C40H34Br4N4Pd2S2 (M = 1167.31): C, 41.16;
H, 2.94; N, 4.80; S, 5.49. Found: C, 41.06; H, 2.76; N, 4.66; S, 5.53.

Dibromo[µ-1,2-bis(4-pyridyl)ethane]bis(3-propylbenzothiazolin-2ylidene)dipalladium(II), 2.16(b)
Complex 2.16(b) was prepared similarly to 2.13(a) from 2.2(b) (100 mg, 0.11 mmol)
and 1,2-bis(4-pyridyl) ethane (21 mg, 0.11 mmol). Yield: 79 mg (0.07 mmol, 65 %).
1

H NMR (500 MHz, CDCl3): δ 8.91 (t, 3JHH = 6.3 Hz, 2H, Ar-H), 8.50 (d, 3JHH = 5.7

Hz, 4H, Ar-H), 7.82 (d, 3JHH = 7.6 Hz, 1H, Ar-H), 7.68 (d, 3JHH = 8.2 Hz, 1H, Ar-H),
7.52 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 7.43 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 7.16 (d, 3JHH =

6.3 Hz, 2H, Ar-H), 7.10-7.07 (m, 4H, Ar-H), 5.14 (t, 3JHH = 7.9, 4H, CH2CH2CH3),
2.94 (s, 4H, CH2CH2), 2.33 (m, 3JHH = 7.9 Hz, 4H, CH2CH2CH3), 1.22 (t, 3JHH = 7.5
Hz, 6H, CH2CH2CH3).

C{1H} NMR (125 MHz, CDCl3): δ 193.2 (NSC), 152.7,

13

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150.0, 149.8, 142.9, 126.7, 125.1, 124.7, 123.8, 123.7, 121.9, 113.8 (Ar-C), 56.9
(CH2CH2CH3), 35.7 (CH2CH2) 21.9 (CH2CH2CH3), 11.7 (CH2CH2CH3); MS (ESI):
990 (30) [M - Br]+. Anal. Calc. for C32H34Br4N4Pd2S2 (M = 1071.23): C, 35.88; H,
3.20; N, 5.23; S, 5.99. Found: C, 35.33; H, 3.34; N, 5.37; S, 5.84.

3.2.6 Synthesis of Complexes 2.17-2.21 (Chapter Two, Section 2.7)

Diiodo(µ-diiodo)bis(3-isopropylbenzothiazolin-2-ylidene)dipalladium(II), 2.17
Complex 2.17 was prepared similarly to 2.2(a) from D (559 mg, 1.00 mmol) and
Pd(OAc)2 (225 mg, 1.00 mmol). Purification by column chromatography using
CH2Cl2 as eluant gave 2.17 as a red solid. Slow evaporation of a concentrated CH2Cl2
solution yielded red crystals suitable for X-ray diffraction studies. Yield: 193 mg
(0.18 mmol, 36%). 1H NMR (500 MHz, DMSO-d6): δ 8.24 (d, 3JHH = 8.2 Hz, 2H, ArH), 8.10 (d, 3JHH = 8.2 Hz, 2H, Ar-H), 7.56 (t, 3JHH = 7.6 Hz, 2H, Ar-H), 7.50 (t, 3JHH

= 7.6 Hz, 2H, Ar-H), 6.22 (m, 3JHH = 7.00 Hz, 2H, CH(CH3)2), 1.80 (d, 3JHH = 7.00
Hz, 12H, CH(CH3)2). 13C{1H} NMR (125 MHz, DMSO-d6): δ 184.0 (s, NCS), 140.7,
137.9, 127.4, 125.6, 123.2, 116.9 (s, Ar-C), 55.4 (s, CH(CH3)2), 18.7 (s, CH(CH3)2).
MS (ESI, positive mode) m/z (%): 1019 (100) [M – I + CH3OH + CH3CN]+. Anal.
Calc. for C20H22I4N2S2Pd2 (M = 1074.99): C, 22.35; H, 2.06; N, 2.61; S, 5.97. Found:
C, 22.67; H, 2.02; N, 2.51; S, 6.30.

trans-diiodo(3-isopr opylbenzothiazolin-2-ylidene)(pyridine)palladium(II), 2.18
Pyridine (5 mL) was added to complex 2.17 (602 mg, 0.06 mmol) and the mixture
was stirred at r.t. overnight. The clear yellow solution thus obtained was evaporated to
dryness under vacuum. The solid product 2.18 was redissolved in CH2Cl2 onto which
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was layered Et2O to give yellow single crystals upon standing. Yield: 678 mg (0.11
mmol, 98%). 1H NMR (500 MHz, CDCl3): δ 9.06 (d, 3JHH = 6.3 Hz, 2H, 2,6-py-H),
7.89 (d, 3JHH = 8.2 Hz, 1H, 4-py-H), 7.75 (m, 2H, 3,5-py-H), 7.44 (t, 3JHH = 7.9 Hz,
1H, Ar-H), 7.38-7.33 (m, 3H, Ar-H), 6.57 (m, 3JHH = 7.1 Hz, 1H, CH(CH3)2), 1.92 (d,
3

JHH = 7.0 Hz, 6H, CH(CH3)2. 13C{1H} NMR (125 MHz, CDCl3): δ 189.4 (s, NCS),

154.1, 141.3, 138.9, 137.8, 126.0, 124.6, 122.2, 115.8 (s, py-C and Ar-C), 63.4 (s,
CH(CH3)2), 19.2 (s, CH(CH3)2). MS (ESI, positive mode) m/z (%): 587 (100) [M – I]+

+ 3CH3OH. Anal. Calc. for C15H16I2N2SPd (M = 616.59): C, 29.22; H, 2.62; N, 4.54;
S, 5.20. Found: C, 30.95; H, 2.66; N, 4.72; S, 5.64.

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(2aminopyridine)palladium(II), 2.19
A mixture of 2.17 (110 mg, 0.10 mmol) and 2-aminopyridine (19 mg, 0.20 mmol)
was suspended in CH2Cl2 (5 mL) and stirred overnight at r.t.. Upon solvent
evaporation under vacuum, the yellow solid was washed with Et2O several times.
Diffusion of Et2O into a concentrated CH2Cl2 solution yielded yellow crystals suitable
for X-ray diffraction studies. Yield: 101 mg (0.16 mmol, 80%). 1H NMR (500 MHz,
CDCl3): δ 7.90 (d, 3JHH = 8.2 Hz, 1H, 2-py-H), 7.78 (m, 1H, 3-py-H), 7.55-7.49 (m,
1H, Ar-H), 7.47-7.42 (m, 2H, Ar-H), 7.41-7.37 (m, 1H, Ar-H), 6.67 (m, 1H, 4-py-H),
6.59 (d, 3JHH = 8.2 Hz, 1H, 5-py-H), 6.54 (m, 3JHH = 7.3 Hz, 1H, CH(CH3)2), 5.38 (s
br, 2H, NH2), 1.94 (d, 3JHH = 7.6 Hz, 6H, CH(CH3)2.

13

C{1H} NMR (125 MHz,

CDCl3): δ 191.6 (s, NCS), 157.9, 149.7, 141.4, 138.5, 137.7, 126.1, 124.6, 122.4,
115.9, 114.1, 108.6 (s, py-C and Ar-C), 63.3 (s, CH(CH3)2), 19.4 (s, CH(CH3)2). MS
(ESI, positive mode) m/z (%): 504 (50) [M – I]+, 1042 (100) 2[M – I]+ + CH3OH.

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Anal. Calc. for C15H17I2N3SPd (M = 631.63): C, 28.52; H, 2.71; N, 6.65; S, 5.08.
Found: C, 28.92; H, 2.69; N, 6.54; S, 5.06.

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(3-iodopyridine)palladium(II),
2.20
Complex 2.20 was prepared as a yellow solid similar to 2.19 from 2.17 (56 mg, 0.05
mmol) and 3-iodopyridine (24 mg, 0.12 mmol). Yellow single crystals of 20 were
obtained from a diffusion of Et2O into a concentrated CH2Cl2 solution. Yield: 58 mg
(0.07 mmol, 70%). 1H NMR (500 MHz, CDCl3): δ 9.32 (s, 1H, 2-py-H), 9.06 (d, 3JHH
= 5.1 Hz, 1H, 5-py-H), 8.07 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 7.90 (d, 3JHH = 8.2 Hz, 1H,
Ar-H), 7.77 (d, 3JHH = 7.6 Hz, 1H, 4-py-H), 7.45 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 7.38 (t,
3

JHH = 7.3 Hz, 1H, Ar-H), 7.14 (t, 3JHH = 6.6 Hz, 1H, 3-py-H), 6.53 (m, 1H, 3JHH =

7.00 Hz, CH(CH3)2), 1.92 (d, 3JHH = 7.00 Hz, 6H, CH(CH3)2).

13

C{1H} NMR (125

MHz, CDCl3): δ 187.8 (s, NCS), 159.6, 152.7, 146.3, 141.2, 138.8, 126.1, 125.5,
124.6, 122.2, 115.9, 91.9 (s, py-C and Ar-C), 63.5 (s, CH(CH3)2), 19.2 (s, CH(CH3)2).
MS (ESI, positive mode) m/z (%): 583 (100) [M - I - CH3OH]+, 742 (50) [M + H]+.
Anal. Calc. for C15H15I3N2SPd.CH2Cl2 (M = 827.42): C, 23.23; H, 2.07; N, 3.39; S,
3.88. Found: C, 22.72; H, 1.90; N, 3.38; S, 4.66.

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(4-tert-butylpyridine)palladium(II), 2.21
Complex 2.21 was prepared as a yellow solid similar to 2.19 from 2.17 (140 mg, 0.13

mmol) and 4-tert-butyl-pyridine (35 mg, 0.26 mmol). Yellow single crystals of 21
were obtained from a diffusion of Et2O into a concentrated CH2Cl2 solution. Yield: 96
mg (0.14 mmol, 15%). 1H NMR (500 MHz, CDCl3): δ 8.93 (d, 3JHH = 6.9 Hz, 2H, 2,
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6-py-H), 7.89 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 7.76 (d, 3JHH = 7.6 Hz, 1H, Ar-H), 7.44 (t,
3

JHH = 7.6 Hz, 1H, Ar-H), 7.37 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 7.31 (d, 3JHH = 6.9 Hz,

2H, 3, 5-py-H), 6.58 (m, 3JHH = 7.1 Hz, 1H, CH(CH3)2), 1.92 (d, 3JHH = 7.0 Hz, 6H,
CH(CH3)2), 1.32 (S, 9H, (CH3)3).

C{1H} NMR (125 MHz, CDCl3): δ 189.9 (s,

13

NCS), 162.4, 153.6, 149.6, 141.3, 138.9, 126.0, 124.5, 122.2, 121.8, 115.8 (s, py-C
and Ar-C), 63.3 (s, CH(CH3)2), 35.1 (CH3)3, 30.3 (CH3)3, 19.2 (s, CH(CH3)2). MS
(ESI, positive mode) m/z (%): 544 (20) [M - I]+, 819 (100) [M - I]+ + 2[tert-butylpyridine], 948 (80) [M - I]+ + 3[tert-butyl-pyridine]. Anal. Calc. for C19H25I2N2SPd
(M = 673.71): C, 33.87; H, 3.74; N, 4.16; S, 4.76. Found: C, 34.42; H, 3.50; N, 4.11;
S, 5.39.

3.2.7 Synthesis of Complexes 2.22-2.27 (Chapter Two, Section 2.8)

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(imidazole-ĸN)Pd(II), 2.22
Complex 2.22 was prepared from the reaction of the parent Pd(II) dinuclear complex
(97 mg, 0.09 mmol) and imidazole (13 mg, 0.18 mmol). The mixture was suspended
in CH2Cl2 (5 mL) and stirred overnight at room temperature. The yellow precipitate
thus obtained was washed several times with Et2O. The yellow solid was obtained.
Yellow single crystals of 2.22 were obtained from a diffusion of Et2O into a
concentrated CH2Cl2 solution. Yield: 97 mg (0.16 mmol, 89%). 1H NMR (500 MHz,
CDCl3): δ 9.47 (s, 1H, NH), 8.41 (s, 1H, NCHN), 7.88 (d, 3JHH = 8.9 Hz, 1H, Ar-H),
7.56 (d, 3JHH = 10.1 Hz, 1H, Ar-H), 7.48-7.34 (m, 2H, Ar-H), 6.98 (s, 2H, NCH=),
6.57 (m, 3JHH = 7.2 Hz, 1H, CH(CH3)2), 1.90 (d, 3JHH = 7.0 Hz, 6H, CH(CH3)2).
C{1H} NMR (125 MHz, CDCl3): δ 191.0 (s, NCS), 141.4 (s, NCHN), 140.7, 138.9,

13

134.9, 132.1, 125.9, 124.5, 121.8, 115.8 (s, Ar-C), 63.1 (s, CH(CH3)2), 19.1 (s,
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CH(CH3)2). MS (ESI, positive mode) m/z (%): 543 (100) [M - I]+ + 2CH3OH. Anal.
Calc. for C13H15I2N3SPd.Et2O.H2O (M = 697.71): C, 29.26; H, 3.90; N, 6.02; S, 4.60.
Found: C, 29.06; H, 3.11; N, 5.61; S, 5.74.

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(1-(2,4,6-trimethyl-phenyl)-1Himidazole -ĸN)Pd(II), 2.23
Complex 2.23 was prepared similarly to 2.22 from the parent Pd(II) dinuclear
complex (108 mg, 0.10 mmol) and 1-(2,4,6-trimethyl-phenyl)1H-imidazole (37 mg,
0.2 mmol). A yellow solid was obtained. Yellow single crystals of 2.23 were obtained
from a diffusion of Et2O into a concentrated CH2Cl2 solution. Yield: 97 mg (0.11
mmol, 55%). 1H NMR (500 MHz, CDCl3): δ 8.27 (s, 1H, NCHN), 7.89 (s, 1H, Ar-H),
7.88 (s, 1H, Ar-H), 7.75 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 7.42 (t, 3JHH = 7.9 Hz, 1H, ArH), 7.35 (t, 3JHH = 7.6 Hz, 1H, Ar-H), 6.97 (s, 2H, NCH=), 6.81 (s, 1H, Ar-H), 6.58
(m, 3JHH = 7.1 Hz, 1H, CH(CH3)2), 2.34 (s, 3H, CH3), 2.17 (s, 3H, CH3), 2.02 (s, 3H,
CH3), 1.91 (d, 3JHH = 7.6 Hz, 6H, CH(CH3)2).

C{1H} NMR (125 MHz, CDCl3): δ

13

190.3 (s, NCS), 143.5 (s, NCHN), 141.4, 139.6, 138.9, 135.1, 133.3, 132.5, 129.2,
125.9, 124.4, 122.1, 120.1, 115.8 (s, Ar-C), 63.1 (s, CH(CH3)2), 21.1 (s, CH3), 19.1 (s,
CH(CH3)2), 17.6 (s, CH3). MS (ESI, positive mode) m/z (%): 1136 (100) [M - I]+ +
2(C12H14N2) + CH3CN. Anal. Calc. for C22H25I2N3SPd.Et2O.CH2Cl2 (M = 882.80): C,
36.73; H, 4.22; N, 4.76; S, 3.63. Found: C, 36.92; H, 4.72; N, 4.59; S, 3.92.

trans-diiodo(3-isopropylbenzothiazolin-2-ylidene)(benzimidazole-ĸN)Pd(II), 2.24
Complex 2.24 was prepared similarly to 2.22 from the parent Pd(II) dinuclear
complex (100 mg, 0.09 mmol) and benzimidazole (22 mg, 0.19 mmol). A yellow
solid was obtained. Yellow single crystals of 2.24 were obtained from a diffusion of
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Et2O into a concentrated CH2Cl2 solution. Yield: 100 mg (0.15 mmol, 82%). 1H NMR
(500 MHz, DMSO-d6): δ 13.33 (s, 1H, NH), 8.78 (s, 1H, NCHN), 8.25 (d, 3JHH = 8.2
Hz, 1H, Ar-H), 8.11 (d, 3JHH = 8.2 Hz, 2H, Ar-H), 7.60-7.55 (m, 2H, Ar-H), 7.50 (t,
3

JHH = 7.6 Hz, 1H, Ar-H), 7.40-7.34 (m, 2H, Ar-H), 6.58 (m, 3JHH = 6.6 Hz, 1H,

CH(CH3)2), 1.90 (d, 3JHH = 7.0 Hz, 6H, CH(CH3)2).

13

C{1H} NMR (125 MHz,

DMSO-d6): δ 192.8 (s, NCS), 144.9 (s, NCHN), 141.2, 140.5, 138.0, 132.5, 127.2,
125.4, 124.1, 123.2, 122.9, 122.3, 120.7, 116.8, 113.0 (s, Ar-C), 62.9 (s, CH(CH3)2),
19.1 (s, CH(CH3)2). MS (ESI, positive mode) m/z (%): 645 (100) [M - I]+ +
benzimidazole, 527 (60) [M-I] +. Anal. Calc. for C17H17I2N3SPd (M = 655.63): C,
31.14; H, 2.61; N, 6.41; S, 4.89. Found: C, 31.27; H, 2.81; N, 6.32; S, 4.43.

trans-diiodo(3-isopr opylbenzothiazolin-2-ylidene)(benzothiazole-ĸN)Pd(II), 2.25
Complex 25 was prepared similarly to 22 from the parent Pd(II) dinuclear complex
(193 mg, 0.18 mmol) and benzothiazole (49 mg, 0.36 mmol). The yellow solid was
obtained. Yellow single crystals of 25 were obtained from a diffusion of Et2O into a
concentrated CH2Cl2 solution. Yield: 155 mg (0.23 mmol, 64%). 1H NMR (500 MHz,
CDCl3): δ 9.46 (s, NCHS, 1H), 8.88 (d, 3JHH = 8.2 Hz, 1H, Ar-H), 7.92 (d, 3JHH = 8.2
Hz, 2H, Ar-H), 7.80 (d, 3JHH = 7.6 Hz, 1H, Ar-H), 7.69 (t, 3JHH = 7.9 Hz, 1H, Ar-H),
7.55 (t, 3JHH = 7.3 Hz, 1H, Ar-H), 7.46 (t, 3JHH = 7.3 Hz, 1H, Ar-H), 7.39 (t, 3JHH =

7.3 Hz, 1H, Ar-H), 6.68 (m, 3JHH = 7.2 Hz, 1H, CH(CH3)2), 1.98 (d, 3JHH = 7.0 Hz,
6H, CH(CH3)2).

13

C{1H} NMR (125 MHz, CDCl3): δ 189.9 (s, NCS), 158.8 (s,

NCHS), 150.2, 141.3, 138.9, 131.7 (s, Ar-C), 126.8 (d, 2/3Jcc = 21.0 Hz, Ar-C), 126.1,
125.7, 124.7 (s, Ar-C), 122.2 (d,

2/3

Jcc = 17.3 Hz, Ar-C), 115.9 (s, Ar-C), 63.7 (s,

CH(CH3)2), 19.5 (s, CH(CH3)2). MS (ESI, positive mode) m/z (%): 586 (90) [M – I +

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