Preparation and structural studies of diphenylthiophosphinito rhodium(III) complexes. X-ray structure analysis of [{(C5Me5)Rh}2(µ-Cl)2(µ-Ph2PS)][BPh4]

Abstract

The tri-µ-hydroxo-dirhodium complex [{(C₅Me₅)Rh}₂(µ-OH)₃][ClO₄](1) reacts with the appropriate amount of Ph₂P(S)H, in acetone, to give [{(C₅Me₅)Rh}₂(µ-OH)_n(µ-Ph₂PS)_3–n][ClO₄][n= O(2) or 1(3)]. Reaction of complex (1) with an equimolar amount of Ph₂P(S)H, in methanol gave the di-µ-methoxo-µ-diphenylthiophosphinito complex [{(C₅Me₅)Rh}₂(µ-OMe)(₂(µPh₂PS)][ClO₄](5). The mixed-bridged complex [{(C₅Me₅)Rh}₂(µ-OMe)(µ-pz)(µ-Ph₂PS)][ClO₄](6)(pz = pyrazolate) was obtained by addition of Ph₂P(S)H to a methanolic solution of [{(C₅Me₅)Rh}₂(µ-OH)(µ- pz)₂]-[ClO₄]. The complexes (5) and [{(C₅Me₅)Rh}₂(µ-OH)(µ-Ph₂PS)₂][ClO₄](3) react with HCl yielding the binuclear chloride compounds [{(C₅Me₅) Rh}₂(µ-Cl)₂(µ-Ph₂PS)][ClO₄](7) and [{(C₅Me₅)Rh}₂(µ-Cl)(µ-Ph₂PS)₂][ClO₄](9). The doubly homo-bridged complex [{(C₅Me₅)-Rh(Bu^tNC)}₂(µ-Ph₂PS)₂][ClO₄], (10) can be prepared from [(C₅Me₅) Rh(acac)(Bu^tNC)][ClO₄](acac = acetylacetonate ion) and an equimolar amount of Ph₂P(S)H. The mononuclear species [(C₅Me₅)Rh(acac)Cl] reacts with an equimolar amount of Ph₂P(S)H in the presence of NaBPh₄ giving the binuclear complex [{(C₅Me₅)Rh}₂(µ-Cl)(µ-Ph₂PS)₂][BPh₄](11). Its n.m.r. spectra show the presence of two isomers. Reaction of [{(C₅Me₅)RhCl}₂(µ-Cl)₂] with Ph₂P(S)H and KOH yields the mononuclear complex [(C₅Me₅)Rh(Ph₂PS-P)(Ph₂PS-PS)](12). This compound is converted by sulphur-atom abstraction into [(C₅Me₅)Rh(Ph₂PS-P)(Ph₂PS₂-SS)](13). The X-ray structure analysis of [{(C₅Me₅)Rh}₂(µ-Cl)₂(µ-Ph₂PS)][BPh₄](8) is also reported: the crystals are triclinic, space group P, and have been refined to R 0.035 and R′ 0.038. The rhodium–rhodium distance is 3.570 1(5)Å.