Novel dinuclear and trinuclear ruthenium clusters derived from 2‐aryl‐substituted indenylphosphines via C─H bond cleavage

Abstract

Treatment of Ru3(CO)12 with an equivalent of (2‐phenyl‐1H‐inden‐3‐yl)dicyclohexylphosphine (1) and (2‐pyridyl‐1H‐inden‐1‐yl)dicyclohexylphosphine (4) in refluxing heptane gave the novel trinuclear ruthenium clusters (μ3‐η1:η2:η5–2‐phenyl‐3‐Cy2PC9H4)Ru3(CO)8 (1c) and [μ2‐η1–2‐(pyridin‐2‐yl)‐3‐Cy2PC9H6]Ru3(CO)9 (4a), respectively, via C─H bond cleavage. (2‐Mesityl‐1H‐inden‐3‐yl)dicyclohexylphosphine (2) reacted with Ru3(CO)12 in refluxing heptane to give the trinuclear ruthenium cluster [μ‐2‐mesityl‐(3‐Cy2PC9H5)](μ2‐CO)Ru3(CO)9 (2c) via C─H bond cleavage and carbonyl insertion. 2‐(Anthracen‐9‐yl)‐1H–inden‐3‐yldicyclohexylphosphine (3) reacted with Ru3(CO)12 in refluxing heptane to give the dinuclear ruthenium cluster [μ2‐η3:η3–2‐(anthracen‐9‐yl)‐3‐Cy2PC9H6]Ru2(CO)5 (3a). The structures of 1c, 2c, 3a and 4a were fully characterized using IR and NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. These results suggest that the 2‐aryl substituent on the indenyl ring has a pronounced effect on the reaction and coordination modes of Ru3(CO)12.