The reactions of C6H5CH(CH3)N-3 with nitrile solvates of the [Re-6(mu(3)-Se)(8)](2+) core-containing cluster, [Re-6(mu(3)-Se)(8)(PEt3)(5)(MeCN)](2+)(1) and cis-[Re-6(mu(3)-Se)(8)(PEt3)(4)(MeCN)(2)](2+) (2), afforded the corresponding cationic imino complexes [Re-6(mu(3)-Se)(8)(PEt3)(5)(PhN=CHCH3)](2+)(3) and cis-[Re-6(mu(3)-Se)(8)(PEt3)(4)(PhN=CHCH3)(2)](2+) (4), respectively. Both compounds were spectroscopically and crystallographically characterized. A mechanism involving a 1,2-shift of one of the groups on the azido alpha-C atom of the cluster-azide intermediate concerted with the photoexpulsion of dinitrogen of the azido ligand is invoked to rationalize the formation of the imino complexes. Density functional theory calculations showed that a cluster-to-ligand transition was responsible for the absorption that promotes the photodecomposition of the cluster-azide complex.