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M. Gozelle et al. / Polyhedron 161 (2019) 298–308
Yield: 56.4%; mp: 267–268 °C (decomp). 1H NMR (DMSO-d6) d
ppm: 13.40 (br s, 2H, 2ꢂ N–H, exchangeable with D2O), 7.79–
7.77 (m, 2H, Ar-H), 7.50–7.48 (m, 2H, Ar-H), 7.29–7.24 (m, 4H,
Ar-H), 5.4 (br s, 1H, CH3CH2OH, exchangeable with D2O), 3.38 (q,
J = 6.8 Hz, 2H, CH3CH2OH), 3.23 (d, J = 7.6 Hz, 4H, 2ꢂ –CH2CH-),
2.74–2.70 (m, 2H, 2ꢂ –CH2CH(CH3)2), 1.11–0.35 (m, 15H, 2ꢂ –CH2-
m
(cmꢀ1): 3507 (H2O), 3186
CH(CH3)2), CH3CH2OH). IR (ATR)
m
(cmꢀ1): 3188 (N–H), 3041
Ar-H), 2.72 (s, 6H, 2ꢂ –CH3). IR (ATR)
(N–H), 3060 (@CAH), 2929 (C–H), 1698, 1647 (C@O), 1225 (C–O),
18H17N4O4Pt:
(@CAH), 2958 (C–H), 320 (Pt–Cl). HRMS (m/z) [MꢀH] calcd for
563 (Pt–O). HRMS (m/z), [MꢀH] calcd for
C
C
C
22H27N4Cl2Pt: 613.1262, found: 613.1249; Anal. Calc. for
22H28N4Cl2PtꢃCH3CH2OH: C, 42.73; H, 4.99; N, 8.67. Found: C,
548.0898, found: 548.0914; Anal. Calc. for C18H16N4O4Ptꢃ0.35H2O:
C, 39.04; H, 3.04; N, 10.12. Found: C, 39.49; H, 3.54; N, 10.52%.
Oxalato-bis(2-isopropylbenzimidazole)platinum(II)] [Pt(L3)2(ox)]ꢃ
0.5CH3CH2OH (3b). The general procedure was followed, using 2-
isopropylbenzimidazole (L3), K2[Pt(ox)2]ꢃ2H2O and a reaction time
of 7 days.
42.82; H, 5.16; N, 8.82%.
Cis-[dichloro-bis(R,S-2-(sec-butyl)benzimidazole)platinum(II)]
[Pt(L5)2Cl2]ꢃ1.5H2O (5a). The general procedure was followed,
using R,S-2-(sec-butyl)benzimidazole (L5), K2PtCl4 and a reaction
time of 6 days.
Yield: 71.8%; mp: 296–297 °C (decomp). 1H NMR (DMSO-d6) d
Yield: 39.3%; mp: 246 °C (decomp). 1H NMR (DMSO-d6) d ppm:
ppm: 13.39 (br s, 2H, 2ꢂ N–H, exchangeable with D2O), 7.98 (s,
2H, Ar-H), 7.53–7.51 (m, 2H, Ar-H), 7.34–7.32 (m, 4H, Ar-H), 4.34
(br s, 0.5H, 0.5ꢂ CH3CH2OH, exchangeable with D2O), 3.97–3.92
and 3.79–3.76 (two separate m, 1.5H ve 0.5H, 2ꢂ –CH-(CH3)2),
3.44 (q, J = 7.2 Hz, 1H, 0.5ꢂ CH3CH2OH), 1.45–1.03 (m, 13.5H, 2ꢂ
13.11 and 12.82 (2ꢂ br s, 2H, 2ꢂ N–H, exchangeable with D2O),
8.37 and 8.01 (2ꢂ d, J = 8.0 Hz, 2H, 2ꢂ Ar-H), 7.55–7.24 (m, 6H,
Ar-H), 3.80–3.37 (m, 2H, 2ꢂ Ar-CH(CH3)CH2CH3), 2.09–1.63 (m,
4H, 2ꢂ –CH(CH3)CH2CH3), 1.44–1.28 (m, 6H, 2ꢂ CH(CH3)CH2CH3),
1.09–0.81 (m, 6H, –CH(CH3)CH2CH3). IR (ATR)
m
(cmꢀ1): 3186 (N–
H), 3059 (@CAH), 2966 (C–H), 323 (Pt–Cl). HRMS (m/z) [MꢀH]
–CH(CH3)2, 0.5ꢂ CH3CH2OH). IR (ATR)
m
(cmꢀ1): 3521 (O–H),
calcd for C22H27N4Cl2Pt: 613.1262, found: 613.1260; Anal. Calc. for
3164 (N–H), 3059 (@CAH), 2970 (C–H), 1695, 1624 (C@O), 1260
(C–O), 560 (Pt–O). HRMS (m/z), [MꢀH] calcd for C23H25N4O4Pt:
604.1524, found: 604.1495; Anal. Calc. for C23H24N4O4Ptꢃ0.5CH3-
CH2OH: C, 43.62; H, 4.23; N, 9.04. Found: C, 44.31; H, 4.97; N,
9.77%.
C
22H28N4Cl2Ptꢃ1.5H2O: C, 41.19; H, 4.87; N, 8.73. Found: C, 41.01;
H, 4.76; N, 8.39%.
Cis-[dichloro-(2-((1H-imidazol-4-yl)methyl)benzimidazole)-
platinum(II)] [Pt(L6)Cl2]ꢃ2H2O (6a). The general procedure was
followed, using 2-((1H-imidazol-4-yl)methyl)benzimidazole (L6),
K2PtCl4 and a reaction time of 6 days.
Oxalato-bis(2-isobutylbenzimidazole)platinum(II)] [Pt(L4)2(ox)]ꢃ
0.2 L4 (4b). The general procedure was followed, using 2-isobutyl-
benzimidazole (L4), K2[Pt(ox)2]ꢃ2H2O and a reaction time of 9 days.
Yield: 64.0%; mp: 299 °C (decomp). 1H NMR (DMSO-d6) d ppm:
Yield: 85.0%; mp: >360 °C. 1H NMR (DMSO-d6) d ppm: 13.73 (br
s, 1H, N–H, exchangeable with D2O), 13.01 (br s, 1H, N–H,
exchangeable with D2O), 8.27–8.16 (m, 2H, Ar-H), 7.57–7.27 (m,
13.37 (br s, 2H, 2ꢂ N–H, exchangeable with D2O), 8.14 (d,
J = 6.8 Hz, 2H, Ar-H), 7.55 (d, J = 7.6 Hz, 2H, Ar-H), 7.43–7.36 (m,
4H, Ar-H), 7.11–7.09 (m, 0.4H, 0.2ꢂ L4 Ar-H), 2.73–2.62 (m, 4H,
2ꢂ –CH2CH), 2.41–2.38 (m, 2H, 2ꢂ –CH2CH(CH3)2), 0.93 (d,
J = 6.4 Hz, 1.2H, 0.2ꢂ L4 –CH(CH3)2), 0.92–0.50 (m, 12H, 2ꢂ CH–
4H, Ar-H), 4.29 (s, 2H, Ar-CH2-Ar). IR (ATR)
m
(cmꢀ1): 3508 (H2O),
3219, 3133 (N–H), 3042 (@CAH), 2976 (C–H), 321 and 317 (Pt–
Cl). HRMS (m/z), [MꢀH] calcd for C11H9N4Cl2Pt: 462.9854, found:
462.9836; Anal. Calc. for C11H10N4Cl2Ptꢃ2H2O: C, 26.41; H, 2.82;
N, 11.20. Found: C, 26.68; H, 2.73; N, 11.06%.
(CH3)2). IR (ATR)
m
(cmꢀ1): 3198 (N–H), 3097 (@CAH), 2960 (C–
Cis-[dichloro-bis(2-((4-hydroxyphenyl)methyl)benzimidazole)-
platinum(II)] [Pt(L7)2Cl2]ꢃ3.25H2O (7a). The general procedure was
followed, using 2-((4-hydroxyphenyl)methyl)benzimidazole (L7),
K2PtCl4 and a reaction time of 2 days.
H), 1710, 1657 (C@O), 1221 (C–O), 564 (Pt–O). HRMS (m/z),
[MꢀH] calcd for C24H27N4O4Pt: 630.1680, found: 630.1690; Anal.
Calc. for C24H28N4O4Ptꢃ0.2 L4: C, 47.22; H, 4.66; N, 9.25. Found: C,
47.37; H, 4.97; N, 9.29%.
Yield: 84.0%; mp: >360 °C. 1H NMR (DMSO-d6) d ppm: 12.16 (br
Oxalato-bis(R,S-2-(sec-butyl)benzimidazole)platinum(II)]
[Pt
s, 2H, 2ꢂ N–H, exchangeable with D2O), 9.26 (br s, 2H, 2ꢂ O–H,
exchangeable with D2O), 7.50–7.38 (m, 8H, Ar-H), 7.11 (d,
J = 8.0 Hz, 4H, Ar-H), 6.69 (d, J = 8.0 Hz, 4H, Ar-H), 4.03 (s, 4H, 2ꢂ
(L5)2(ox)]ꢃ0.5H2O (5b). The general procedure was followed, using
R,S-2-(sec-butyl)benzimidazole (L5), K2[Pt(ox)2].2H2O and a reac-
tion time of 7 days.
Yield: 77.8%; mp: 308 °C (decomp). 1H NMR (DMSO-d6) d ppm:
Ar-CH2-Ar). IR (ATR)
3053 (@CAH), 2958 (C–H), 1224 (C–O), 325 and 318 (Pt–Cl). HRMS
28H23N4O2Cl2Pt: 713.0848, found:
m
(cmꢀ1): 3528 (O–H and H2O), 3193 (N–H),
13.32 (br s, 2H, 2ꢂ N–H, exchangeable with D2O), 8.10 (br s, 2H,
Ar-H), 7.52 (m, 2H, Ar-H), 7.37–7.36 (m, 4H, Ar-H), 3.52 (m, 2H,
2ꢂ –CH(CH3)CH2CH3), 2.00–1.10 (m, 10H, 2ꢂ –CH(CH3)CH2CH3,
2ꢂ CH(CH3)CH2CH3), 1.0–0.7 (m, 6H, 2ꢂ –CH(CH3)CH2CH3). IR
(m/z), [MꢀH] calcd for
C
713.0868; Anal. Calc. for C28H24N4O2Cl2Ptꢃ3.25H2O: C, 43.50; H,
3.98; N, 7.25. Found: C, 43.82; H, 3.67; N, 6.92%.
General procedure for the preparation of complexes 2b–7b: To a
solution the appropriate 2-substituted benzimidazole (1.8 mmol
for monodentate ligands; 0.9 mmol for bidentate ligands) in etha-
nol/isopropanol (10 ml) at 50–60 °C, a solution of K2[Pt(ox)2]ꢃ2H2O
(1 mmol) in water (10 ml) at 50–60 °C was added dropwise, and
the mixture was stirred at 60–70 °C until complexation was fin-
ished, as judged by TLC and LC–MS. The precipitate was filtered
and the crude product was washed with hot water (70 °C), cold
water (4–5 °C), hot ethanol/isopropanol (70 °C), cold ethanol/iso-
propanol (4–5 °C) and then diethyl ether (4–5 °C). The purified
complex was dried in vacuo.
(ATR)
m
(cmꢀ1): 3570 (O–H), 3184 (N–H), 3041 (@CAH), 2970
(C–H), 1694, 1650 (C@O), 1252 (C–O), 561 (Pt–O). HRMS (m/z),
[MꢀH] calcd for C24H27N4O4Pt: 630.1680, found: 630.1674; Anal.
Calc. for C24H28N4O4Ptꢃ0.5H2O: C, 45.00; H, 4.56; N, 8.75. Found:
C, 44.93; H, 4.64; N, 9.06%.
Oxalato-bis(2-((1H-imidazol-4-yl)methyl)benzimidazole)plat-
inum(II)] [Pt(L6)(ox)]0.0.3CH3CH2OH (6b). The general procedure
was followed, using 2-((1H-imidazol-4-yl)methyl)benzimidazole
(L6), K2[Pt(ox)2]ꢃ2H2O and a reaction time of 8 days.
Yield: 82.0%; mp: 290–291 °C. 1H NMR (DMSO-d6) d ppm: 13.70
Oxalato-bis(2-methylbenzimidazole)platinum(II)] [Pt(L2)2(ox)]ꢃ
0.35H2O (2b). The general procedure was followed, using 2-
methylbenzimidazole (L2), K2[Pt(ox)2]ꢃ2H2O and a reaction time
of 9 days.
(br s, 1H, N–H, exchangeable with D2O), 13.20 (s, 1H, N–H,
exchangeable with D2O), 8.20 (d, J = 1.2 Hz, 1H, Ar-H), 7.97–7.94
(m, 1H, Ar-H), 7.62–7.60 (m, 1H, Ar-H), 7.45–7.36 (m, 3H, Ar-H),
4.39 (s, 2H, Ar-CH2-Ar), 3.42 (q, J = 6.8 Hz, 0.6H, 0.3ꢂ CH3CH2OH),