B-N Bond Formation by the Reaction of (N-(3-Methoxysalicylidene)-N′-(imidazol-4-ylmethylene)-1,3-propanediamino)copper(II) Perchlorate and Sodium Tetraphenylborate

The copper(II) complex (N-(3-methoxysalicylidene)-N′-(imidazol-4-ylmethylene)-1,3-propanediamino)copper-(II) Perchlorate, [Cu(HL)]ClO₄ (1), reacts with sodium tetraphenylborate (NaBPh₄) in N,N-dimethylformamide to give an electrically neutral complex exhibiting a B-N bond, [Cu(LBPh₃)]·DMF (2). The syntheses and the crystal structures of 1, 2, and the N-memylimidazole adduct of 2, [Cu(LBPh₃)(N-MeIm)] (3), are reported. Crystal data: 1, triclinic, P1, a = 11.842(5) Å, b = 12.074(7) Å, c = 7.000(2) Å, α = 92.35(4)°, β = 96.63(3)°, γ = 115.16-(3)°, Z = 2; 2, triclinic, P1, a = 16.716(6) Å, b = 18.148(4) Å, c = 12.717(2) Å, α = 106.31(2)°, β = 104.67-(3)°, γ = 66.20(3)°, Z = 4; 3, monoclinic, P2₁/n, a = 11.945(8) Å, b = 12.025(9) Å, c = 23.638(4) Å, β = 99.14(3)°, Z = 4. The most striking feature of 2 and 3 is the formation of a B-N bond, in which the boron atom bonds to the nitrogen atom of the imidazolate moiety of the copper(II) complex and to three carbon atoms of the phenyl groups.