The Simple Hexapyridine Cluster [Mo6Br8Py6][OSO2CF3]4 and Substituted Hexapyridine Clusters Including a Cluster-cored Polyolefin Dendrimer


  • Dedicated to Professor Herbert W. Roesky at the Occasion of his 70th Birthday


The yellow octahedral molybdenum cluster [n-Bu4N]2[Mo6Br8(CF3SO3)6], (1); undergoes substitution of all six terminal triflate ligands by pyridine ligands in pyridine/THF at 60 °C to yield the orange hexapyridine cluster [Mo6Br8(Py)6][CF3SO3]4, (2). The cluster 1 also reacts in THF at 60 °C with excessof the para-substitued pyridines 4-tert-Bupy and 4-vinylpy to give the orange para-substituted hexapyridine clusters [Mo6Br8(p-Py-R)6][CF3SO3]4 (3: R = tert-Bu; 4: R = vinyl) and with the new dendronic pyridine derivative 3,3′-{CH2Op-C6H4C(CH2CH=CH2)3}2Py, (5) (7 d), to give the orange relatively air stable Mo6-cluster-cored 36-allyl dendrimer [Mo6Br8(3,5-{CH2OC6H4C(CH2CH=CH2)3}2Py)6][CF3SO3]4, (6). All these substitution reactions were easily monitored by 1H NMR in CDCl3 using the comparison between the intensities of the tetrabutylammonium cation and deshielded coordinated pyridine signals.