Complexation and C–H bond activation of 2,2′:6′,2″-terpyridyl molecules on triosmium carbonyl clusters: Synthesis and characterization of the double-cluster {Cp3Fe4(CO)4(C5H4-terpyridyl)Os3(μ-H)(CO)n} (n = 9, 10)

Cp3Fe4(CO)4(4′-C5H4-2,2′:6′,2″-terpyridine) (abbreviated as Fe4tpyH) reacts with Os3(CO)10(NCMe)2 in hot methylcyclohexane to generate the double cluster (μ-H)Os3(μ,η2-Fe4tpy)(CO)10 (1) and (μ-H)Os3(μ,η3-Fe4tpy)(CO)9 (2). Similar reaction of 4′-(p-FC6H4)-2,2′:6′,2″-terpyridine (abbreviated as FtpyH) and Os3(CO)10(NCMe)2 affords (μ-H)Os3(μ,η2-Ftpy)(CO)10 (3) and (μ-H)Os3(μ,η3-Ftpy)(CO)9 (4). On the other hand, treating the pristine molecule 2,2′:6′,2″-terpyridine (abbreviated as TpyH) with Os3(CO)10(NCMe)2 only isolates (μ-H)Os3(μ,η2-Tpy)(CO)10 (5). These compounds are generated by complexation and C–H bond activation of pyridyl groups on triosmium framework, and have been characterized by IR, NMR, and mass spectroscopies. The structure of 4 is determined by a single-crystal X-ray diffraction study.