Synthesis and spectral studies on Ru 3(CO) 12−n(μ-Ph 2AsCH 2AsPh 2)(L) ( n = 3, L : PPh 3, PCy 2Ph,P(OCH 3) 3); n = 4, L = Ph 2PCH 2PPh 2) : crystal and molecular structures of Ru 3(CO) 9(μ-Ph 2AsCH 2AsPh 2)(PCy 2Ph) and Ru 3(CO) 8(μ-Ph 2AsCH 2AsCH 2AsPh 2)μ-Ph 2PCH 2PPh 2)

Abstract

Mixed ligand triangulotriruthenium cluster carbonyls, Ru 3(CO) 9(μ-Ph 2AsCH 2AsPh 2)(L) (L = PPh 3, PCy 2Ph, P(OCH 3) 3) and Ru 3(CO) 8(μ-Ph 2AsCH 2AsPh 2)(μ-Ph 2PCH 2PPh 2) were synthesised and characterised by microanalysis, IR, 1H, 13C and 31P NMR spectrometry. Single crystal X-ray structure determination of Ru 3(CO) 9(μ-Ph 2AsCH 2AsPh 2)(PCy 2Ph) and Ru 3(CO) 8(μ-Ph 2AsCH 2AsPh 2(μ-Ph 2PCH 2PPh 2) are reported. In both the clusters, the triruthenium framework is planar. In Ru 3(CO) 9(μ-Ph 2AsCH 2AsPh 2)(PCy 2Ph), the monodentate phosphine occupies an equatorial position for steric reasons. The effect of trisubstitution is explicit in the highly significant differences observed in RuRu distances (2.8301 (6), 2.8653(7) and 2.8873(7) Å) in the present compound compared to Ru 3(CO) 10(μ-Ph 2AsCH 2AsPh 2). The observed RuAs distances are 2.4508(7) and 2.4331(7) Å respectively and the RuP distance is 2.362(1) Å. In the case of Ru 3(CO) 8(μ-Ph 2AsCH 2AsPh 2)(μ-Ph 2PCH 2PPh 2), the chelating ligands occupy four equatorial positions. Two of the RuRu distances are similar in length (2.848(2), 2.850(2) and 2.828(2) Å). However, positional disorder is associated with As and P atoms. Other bond parameters are normal.