Crystallographic characterization of rare-earth cyano­tri­phenyl­borate complexes and the cyano­borates [NCBPh(3)](1−), [NCBPh(2)Me](1−), and [NCBPh(2)(μ-O)BPh(2)](1−)

The investigation of the coordination chemistry of rare-earth metal complexes with cyanide ligands led to the isolation and crystallographic characterization of the Ln (III) cyano­tri­phenyl­borate complexes di­chlorido­(cyano­tri­phenyl­borato-κN)tetra­kis­(tetra­hydro­furan-κO)lanthanide(III), [LnCl(2)(C(19)H(15)BN)(C(4)H(8)O)(4)] [lanthanide (Ln) = dysprosium (Dy) and yttrium Y)] from reactions of LnCl(3), KCN, and NaBPh(4). Attempts to independently synthesize the tetra­ethyl­ammonium salt of (NCBPh(3))(−) from BPh(3) and [NEt(4)][CN] in THF yielded crystals of the phenyl-substituted cyclic borate, tetra­ethyl­aza­nium 2,2,4,6-tetra­phenyl-1,3,5,2λ(4),4,6-trioxatriborinan-2-ide, C(8)H(20)N(+)·C(24)H(20)B(3)O(3) (−) or [NEt(4)][B(3)(μ-O)(3)(C(6)H(5))(4)]. The mechanochemical reaction of BPh(3) and [NEt(4)][CN] without solvent produced crystals of tetra­ethyl­aza­nium cyano­diphenyl-λ(4)-boranyl di­phenyl­borinate, C(8)H(20)N(+)·C(25)H(20)B(2)NO(−) or [NEt(4)][NCBPh(2)(μ-O)BPh(2)]. Reaction of BPh(3) and KCN in THF in the presence of 2.2.2-cryptand (crypt) led to a crystal of bis­[(2.2.2-cryptand)potassium] 2,2,4,6-tetra­phenyl-1,3,5,2λ(4),4,6-trioxatriborinan-2-ide cyano­methyl­diphenyl­borate tetra­hydro­furan disolvate, 2C(18)H(36)KN(2)O(6) (+)·C(24)H(20)B(3)O(3) (−)·C(14)H(13)BN(−)·2C(4)H(8)O or [K(crypt)](2)[B(3)(μ-O)(3)(C(6)H(5))(4)][NCBPh(2)Me]·2THF. The [NCBPh(2)(μ-O)BPh(2)](1−) and (NCBPh(2)Me)(1−) anions have not been structurally characterized previously. The structure of 1-Y was refined as a two-component twin with occupancy factors 0.513 (1) and 0.487 (1). In 4, one solvent mol­ecule was disordered and included using multiple components with partial site-occupancy factors.