The syntheses and characterisation of, and the determination of1J(103Rh–103Rh) in [(η5-C5Me5)2Rh2(µ-CH2)2{µ-CH2CR(CH2CRCH2)CH2}](R = H or Me) and [(η5-C5Me5)2Rh2(µ-CH2)2{µ-Ph2P(CH2)nPPh2}]2+(n= 1 or 2)

Abstract

Reaction of [(η5-C5Me5)2Rh2(µ-CH2)2Cl2] with CH2CRCH2MgCl gave [(η5-C5Me5)2Rh2(µ-CH2)2{µ-CH2CR(CH2CRCH2)CH2}](3, R = H; 4, R = Me). Reaction of [(η5-C5Me5)2Rh2(µ-CH2)2(MeCN)2]2+ with Ph2P(CH2)nPPh2gave [(η5-C5Me5)2Rh2(µ-CH2)2{µ- Ph2P(CH2)nPPh2}]2+(5, n= 1; 6, n= 2). The complexes (3)–(6) were characterised largely by their n.m.r. spectra which also allowed the determination of 1J(103Rh–103Rh) as 13.5 for (3), 13.2 for (4), 12.4 for (5), and 11.9 Hz for (6). After allowance for gyromagnetic ratios and s-electron densities at the nuclei, these coupling constants are comparable with a 1J(l95Pt–195Pt) coupling of ca. 8 000 Hz.