[PPN]2[Cr2(CO)10], a Salt of the Dimeric Cr1− Carbonyl Complex Without a Coordinating Counterion

The Cr(1−) carbonyl complex bis[bis(triphenylphosphine)iminium] decacarbonyldichromate(2−), [PPN]2[Cr2(CO)10], (1), where [PPN]+ is [(Ph3P)2N]+, has been prepared by naphthalenide reduction of a Cr0 precursor followed by counterion metathesis to introduce a non-coordinating cation. The [Cr2(CO)10]2− dianion in (1) is structurally similar to that in a previously characterized salt with a [K(DME)2]+ counterion (DME = dimethylethane), despite the loss of the solid-state ion-pairing present in the [K(DME)2]+ salt.