Inorganic Chemistry, Vol.34, No.20, 4996-5002, 1995
Syntheses and Cd-113 NMR-Studies of 5-Coordinate Complexes with Cdn5, Cdn3O2, and Cdn3S2 Central Cores - Solid-State Structures of (HB(3-Phpz)(3))Cd(H2B(3,5-Me(2)Pz)(2)) and (HB(3,5-Me(2)Pz)(3))Cd(S(2)Cnet(2)) (Pz Equals Pyrazolyl)
The reaction of CdCl2 with equimolar amounts of K[HB(3,5-Me(2)pz)(3)] (pz = pyrazolyl) and K[H2B(3,5-Me(2)pz)(2)] or K[HB(3-Phpz)(3)] and either K[H2B(pz)(2)] or K[H2B(3,5-Me(2)pz)(2)] yields, respectively, the five-coordinate complexes [HB(3,5-Me(2)pz)(3)]Cd[H2B(3,5-Me(2)pz)(2)] (1), [HB(3-Phpz)(3)]Cd[H2B(pz)(2)] (2), and [HB(3-Phpz)(3)]Cd[H2B(3,5-Me(2)pz)(2)] (3). The structure of 3 has been characterized in the solid state by X-ray crystallography. The complex has a square pyramidal arrangement of the nitrogen donor atoms about cadmium. Solution state H-1 NMR studies indicate that this geometry is retained in solution. Complexes 1-3 show solution Cd-113 NMR resonances in the range delta 193.6-224.3 ppm (vs Cd(ClO4)(2)). The complexes containing the [HB(3-Phpz)(3)](-) ligand have the more shielded resonances. This range overlaps the region observed for poly(pyrazolyl)borate complexes with CdN6 inner cores (delta 94.0-221.1 ppm). Six complexes with a CdN3O2 inner core of the formula [HB(3-Phpz)(3)]Cd[(RCO)(2)CH] (R = Bu(t), Ph, CF3), [HB(3-Bu(t)pz)(3)]Cd[(Bu(t)CO)(2)CH], [B(3-Pr(i)pz)(4)]Cd[(Bu(t)CO)(2)CH], and [HB(3-Bu(t)pz)(3)]Cd(CH3CO2) have been prepared by the reaction of CdCl2 or Cd(NO3)(2) and the appropriate ligand salts. These complexes show solution Cd-113 NMR resonances in the range delta 141.8-179.8 ppm, with the [(Bu(t)CO)(2)CH](-) ligand complexes the most deshielded and [HB(3-Phpz)(3)]Cd[(CF3CO)(2)CH] the most shielded. Two complexes with N3S2 inner cores, [HB(3,5-Me(2)pz)(3)]Cd[Et(2)NCS(2)] (10) and [HB(3-Phpz)(3)]Cd[Et(2)NCS(2)] (11), have been prepared. The structure of 10 has been determined by X-ray crystallography. The donor atoms are arranged about cadmium in an irregular five-coordinate geometry. Complex 10 shows a solution Cd-113 signal at delta 265.7 and 11 at 237.5 ppm. Crystal data : [HB(3-Phpz)(3)]Cd[H2B(3,5-Me(2)pz)(2)], triclinic, P (1) over bar, a = 11.713(3) Angstrom b = 12.785(3) Angstrom, c = 12.922(4) Angstrom, alpha = 102.57(3)degrees, beta = 104.53(3)degrees, gamma = 91.83(4)degrees, V = 1821(9) Angstrom(3), Z = 2, T = 298 K, R(F) = 3.74%; [HB(3,5-Me(2)pz)(3)]Cd[Et(2)NCS(2)], monoclinic, P2(1)/c, a = 16.707(7) Angstrom, b = 8.197(5) Angstrom, c = 20.280(11) Angstrom, beta = 111.06(4)degrees, V = 2584(5) Angstrom(3), Z = 4, T = 296 K, R(F) = 3.70%.