Coupling of CpCr(CO)3 and Heterocyclic Dithiadiazolyl Radicals. Synthetic, X-ray Diffraction, Dynamic NMR, EPR, CV, and DFT Studies
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- 作者：Hiu Fung Lau ; Pearly Chwee Ying Ang ; Victor Wee Lin Ng ; Seah Ling Kuan ; Lai Yoong Goh ; Alexey S. Borisov ; Paul Hazendonk ; Tracey L. Roemmele ; René ; T. Boeré ; Richard D. Webster
- 刊名：Inorganic Chemistry
- 出版年：2008
- 出版时间：January 21, 2008
- 年：2008
- 卷：47
- 期：2
- 页码：632 - 644
- 全文大小：355K
- 年卷期：v.47,no.2(January 21, 2008)
- ISSN：1520-510X
文摘
The reaction of the 1,2,3,5-dithiadiazolyls (4-R-C6H4CN2S2)2 (R = Me, 2a; Cl, 2b; OMe, 2c; and CF3, 2d) and(3-NC-5-tBu-C6H3CN2S2)2 (2e) with [CpCr(CO)3]2 (Cp = 
5-C5H5) (1) at ambient temperature respectively yieldedthe complexes CpCr(CO)2(2-S2N2CC6H4R) (R = 4-Me, 3a; 4-Cl, 3b; 4-OMe, 3c; and 4-CF3, 3d) and CpCr(CO)2(2-S2N2CC6H3-3-(CN)-5-(tBu)) (3e) in 35-72% yields. The complexes 3c and 3d were also synthesized via a saltmetathesis method from the reaction of NaCpCr(CO)3 (1B) and the 1,2,3,5-dithiadiazolium chlorides 4-R-C6H4CN2S2Cl (R = OMe, 8c; CF3, 8d) with much lower yields of 6 and 20%, respectively. The complexes werecharacterized spectroscopically and also by single-crystal X-ray diffraction analysis. Cyclic voltammetry experimentswere conducted on 3a-e, EPR spectra were obtained of one-electron-reduced forms of 3a-e, and variabletemperature 1H NMR studies were carried out on complex 3d. Hybrid DFT calculations were performed on themodel system [CpCr(CO)2S2N2CH] and comparisons are made with the reported CpCr(CO)2(
-allyl) complexes.
5-C5H5) (1) at ambient temperature respectively yieldedthe complexes CpCr(CO)2(2-S2N2CC6H4R) (R = 4-Me, 3a; 4-Cl, 3b; 4-OMe, 3c; and 4-CF3, 3d) and CpCr(CO)2(2-S2N2CC6H3-3-(CN)-5-(tBu)) (3e) in 35-72% yields. The complexes 3c and 3d were also synthesized via a saltmetathesis method from the reaction of NaCpCr(CO)3 (1B) and the 1,2,3,5-dithiadiazolium chlorides 4-R-C6H4CN2S2Cl (R = OMe, 8c; CF3, 8d) with much lower yields of 6 and 20%, respectively. The complexes werecharacterized spectroscopically and also by single-crystal X-ray diffraction analysis. Cyclic voltammetry experimentswere conducted on 3a-e, EPR spectra were obtained of one-electron-reduced forms of 3a-e, and variabletemperature 1H NMR studies were carried out on complex 3d. Hybrid DFT calculations were performed on themodel system [CpCr(CO)2S2N2CH] and comparisons are made with the reported CpCr(CO)2(-allyl) complexes.