Abstract
The theoretically characterized (DFT) C4 cumulenic species Mn(C5H4R)(dmpe) [=C=C=C=C(SnPh3)2] was obtained by photolysis of the C(sp2)-Sn bond in the vinylidene complex Mn(C5H4R)(dmpe)[=C=C(SnPh3)-C[triple bond]CSnPh3], which in turn was prepared by a thermal reaction from MnC5H4R(dmpe)(C7H8) and Ph3Sn-C4-SnPh3.