Reactivity of hemi-labile pyridyl and pyrimidyl derived chalcogen ligands towards group 10 metal phosphine precursors
An invariable thrust to understand the reactivity of hemilabile organoselenide and telluride ligand system made this area of interest more popular. To resolve the purpose various metal system has been applied. Among them group 10 metal precursors have been exploited dominantly compared to rest of others due to the importance of resulting complex as a catalyst, a good semiconductor and supercapacitor material. The widen applicability of these compounds drive us to explore chemistry of N-Heterocyclic based ligand system. Overall this perspective deals with the reactivity of N-Heterocyclic dichalcogenide Ar2E2 (Ar = C5H4N,C5H3(3-Me)N, C4H3N2, C4H(4,6-Me)N2; E= Se, Te) and their sodium salts (generated by the reductive cleavage of E-E bond through NaBH4) towards group 10 metal phosphine precursors via oxidative addition and substitution route. The oxidative addition reactions of [M(P-P)2] (M = Pd, Pt) / substitution reaction of [MCl2(P-P)] ( M = Ni, Pd, Pt) with diorgano dichalcogenide/ sodium salt of N-heterocyclic selenolate ligands afforded exclusively mononuclear compound [M(SeAr)2(P-P)] (M = Ni, Pd, Pt; Ar = C5H4N,C5H3(3-Me)N, C4H3N2, C4H(4,6-Me)N2 ; P-P = dppe, dppp, dppf) however, pyrimidyl selenolate derived mononuclear compounds which on prolonged stand in chlorinated solvent transformed to trinuclear product. In contrary to selenium analogues, mono to tri all probable nuclearity complexes have been isolated depending upon the metal, phosphine and nature of solvent. The isolation of various products results due to comparable bond dissociation energy of Te-Te and Te-C bond. Among these a ferrrocenyl auxiliary phosphine ligand based mono nuclear tellurolate compound [Pd(TeC5H4N)2(dppf)] has been used for H2S gas sensor application. The efficiency of the thin film of this compound is 75% with the sensitivity till 5 ppm at room temperature.
- This article is part of the themed collection: Selenium & Tellurium chemistry at the beginning of the 3rd millennium: a celebration of ICCST