Tetrakis(acetonitrile)copper(I) tetrafluoroborate is a complex compound of copper with acetonitrile as the ligand and tetrafluoroborate as the counterion.

The nitrosyl salt is then reacted with metallic copper in acetonitrile, initially producing a green-blue copper(II) complex.

[1] Tetrakis(acetonitrile)copper(I) tetrafluoroborate forms colorless crystals in the orthorhombic crystal system in the space group Pna21 with the lattice parameters a = 23.882 Å; b = 8.3285 Å; c = 20.338 Å, and twelve unit cells.

The compound is isomorphous with tetrakis(acetonitrile)copper(I) perchlorate and tetrakis(acetonitrile)silver(I) perchlorate.

[2] Tetrakis(acetonitrile)copper(I) tetrafluoroborate can be reacted with methoxyisobutyl isonitrile to produce Tetrakis(methoxyisobutyl isonitrile)copper(I) tetrafluoroborate.