Compounds in which the Mo24+ unit is embraced by one, two or three formamidinate ligands together with acetonitrile ligands
Abstract
The cationic complexes [Mo2(DPhF)(MeCN)6]3+[BF4–]3·MeCN 1a [throughout this paper the formamidinate anions, RNC(H)NR–, will be abbreviated as DRF–, with specific aryl groups represented by Ph for phenyl, and Ani for p-anisyl], [Mo2(DAniF)(MeCN)6]3+[BF4–]3·1.59MeCN 1b, cis-[Mo2(DPhF)2(MeCN)4]2+[BF4–]2·MeCN 2a, cis-[Mo2(DAniF)2(MeCN)4]2+[BF4–]2·2MeCN 2b, and [Mo2(DPhF)3(MeCN)2]+[BF4–] 3, have been prepared from the reactions between Mo2(DArF)4 and HBF4·Et2O or (Me3O)BF4 in an appropriate stoichiometry in acetonitrile or CH2Cl2–MeCN mixtures. A better procedure for the preparation of 3 involves the reaction between 2a and Li+(DPhF–) in acetonitrile. Compound 2a undergoes a reaction in pyridine to give the compound trans-[Mo2(DPhF)2(py)4]2+[BF4–]2 4. The new compounds 1a, 1b, 2a, 2b and 4 have been structurally characterized and shown to contain Mo–Mo quadruple bonds.