[Ga@Bi 10 (NbMes) 2 ] 3- : a linear Nb-Ga I -Nb filament coordinated by a bismuth cage.

In this work, we report a low-valent Ga(I) complex, [Ga@Bi 10 (NbMes) 2 ] 3- , with a linear Nb-Ga-Nb fragment, representing the first compound with Nb-Ga and Nb-Bi bonds. Quantum-chemical calculations reveal that the complex is an electron-precise cluster. The possible fragmentation pathway of the title cluster was studied by using electrospray ionization mass spectrometry and theoretical calculations.