Synthesis and electronic structure of rigid rod octahedral Ru-?-acetylide complexes

Article abstract of DOI:10.1016/0022-328X(94)80211-4

Syntheses of the mono-, bis- and poly-nuclear Ru-?-acetylide complexes, trans-nBu3)2(-C<*>C-C6H5)2>, trans-nBu3)2-C<*>C-p-C6H4-C6H4-p-C<*>C-Ru(CO)2(PⁿBu3)2Cl> and trans-<-Ru(CO)2(PⁿBu3)2-C<*>C-R-C<*>C->n (R = p-C6H4, p-(CH3)2C6H2) are reported.A study of the electronic structure of model metal-acetylide complexes of Group 8, M(L)2(L')2(RH)2, ClRu(L or L')R-Ru(L or L')4Cl, 2R and n (M = Fe, Ru; L = L' = PH3, PMe3; L = CO, L' = PH3; R = -C<*>C-, -C<*>C-C6H4-C<*>C-, -CH=CH-p-C6H4-CH=CH-) has been carried out using the Fenske-Hall molecular orbital model.These results and a comparison of the IR (ν_C<*>C stretching frequencies) and optical absorption (?-?^* energy band gap) spectra of these complexes provide evidence for the role of (i) auxiliary ligands, (ii) metal, and (iii) the bridging alkyne units in determining the extent of ?-electron conjugation in the backbone of these rigid rod organometallic complexes. Key words: Ruthenium; Electronic structure; Molecular orbital calculations; Polymer; Acetylene; Phosphine