Ruthenium Complexes of Thiaporphyrin and Dithiaporphyrin

• Published in: Inorganic chemistry 2011-12, Vol.50 (23), p.11947-11957
• Main Authors: Chuang, Chuan-Hung, Ou, Chen-Kuo, Liu, Shan-Tung, Kumar, Anil, Ching, Wei-Min, Chiang, Pei-Chun, dela Rosa, Mira Anne C, Hung, Chen-Hsiung
• Format: Article
• Language: English
• Subjects: Crystallography, X-Ray; Ligands; Models, Molecular; Molecular Conformation; Nitrates - chemistry; Nitriles - chemistry; Nitrites - chemistry; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Porphyrins - chemistry; Ruthenium - chemistry; Sulfur - chemistry
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic200977n

Successful synthesis and characterization of the six-coordinated complex [Ru(STTP)(CO)Cl] (1; STTP = 5,10,15,20-tetratolyl-21-thiaporphyrinato) allowed the development of the coordination chemistry of ruthenium–thiaporphyrin through dechlorination and metathesis reactions. Accordingly, [RuII(STTP)(CO)X] (X = NO3 – (2), NO2 – (3), and N3 – (4)) was synthesized and analyzed by single-crystal X-ray structural determination and NMR, UV–vis, and FT-IR spectroscopic methods. An independent reaction of STPPH and [Ru(COD)Cl2] led to [RuIII(STTP)Cl2] (5), which possessed a higher-valent Ru(III) center and exhibited good stability in the solution state. This stability allowed reversible redox processes in a cyclic voltammetric study. Reactions of [Ru(S2TTP)Cl2] (S2TTP = 5,10,15,20-tetratolyl-21,23-dithiaporphyrinato) with AgNO3 and NaSePh, also via the metathesis strategy, resulted in novel dithiaporphyrin complexes [RuII(S2TTP)(NO3)2] (6) and [Ru0(S2TTP)(PhSeCH2SePh)2] (7), respectively. The structures of 6 and 7 were corroborated by X-ray crystallographic analyses. Complex 7 is an unprecedented ruthenium(0)–dithiaporphyrin with two bis(phenylseleno)methanes as axial ligands. A comparison of the analyses of the crude products from reactions of NaSePh and CH2Cl2 with or without [Ru(S2TTP)Cl2], further supported by UV–vis spectral changes under stoichiometric reactions between [Ru(S2TTP)Cl2] and NaSePh, suggested a reaction sequence in the order of (1) formation of a putative [RuII(S2TTP)(SePh)2] intermediate, followed by (2) the concerted formation of PhSe–CH2Cl and simultaneously a reduction of Ru(II) to Ru(0) and finally (3) nucleophilic substitution of PhSeCH2Cl by excess PhSe–, resulting in PhSeCH2SePh, which readily coordinated to the Ru(0) and completed the formation of bis(phenylseleno)methane complex 7.