On reactions of hexachlorodiberyllate with trimethylsilyl-N-dimethylamide. crystal structures of (Ph4P)3[Be2Cl5(OSiMe3)][BeCl3(Me2NSiMe3)], (Ph4P[BeCl3(HNMe2)], and (Ph4P)(H2NMe2)[BeCl4]

Reactions of bis-tetraphenylphosphonium hexachlorodiberyllate, (Ph4P)(2)[Be2Cl6], with trimethylsilyl-N-dimethylamide under different conditions lead to the novel chloroberyllate derivatives (Ph4P)(3)[Be2Cl5(OSiMe3)][BeCl3(Me2NSiMe3)] (1), (Ph4P)[BeCl3-(HNMe2)] (2), and (Ph4P)(H2NMe2)[BeCl4] (3). 1-3 were characterized by IR spectroscopy and crystal structure determinations. 1(.)4CH(2)Cl(2): Space group P (1) over bar, Z = 2, lattice dimensions at 193 K: a = 1115.6(1), b = 2110.7(2), c = 2145.0(3) pm, alpha = 71.38(1)degrees, beta = 85.66(1)degrees, gamma = 85.24(1)degrees, R-1 = 0.0732. The [Be2Cl5(OSiMe3)](2-) ion in the structure of 1 is derived from the [Be2Cl6](2-) ion by substitution of a mu-Cl ligand by the oxygen atom of the (OSiMe3)(-) group. The second anion, [BeCl3(Me2NSiMe3)](-), can be described as donor acceptor complex with a short Be-N bond of 179(1) pm. 2: Space group P (1) over bar, Z = 2, lattice dimensions at 193 K: a = 1063.1(1), b = 1072.0(1), c = 1238.3(1) pm, alpha = 87.55(1)degrees, beta 74.86(1)degrees, gamma = 69.73(1)degrees, R-1 = 0.0299. The anion of 2 forms a centrosymmetric dimer [BeCl3(HNMe2)](2)(2-) via N-(HCl)-Cl-... bridges of the two donor acceptor complex units with Be-N separations of 175.2(2) pm. 3: Space group Pbca, Z = 8, lattice dimensions at 193 K: a = 926.9(1) b = 2164.7(1), c 2732.7(1) pm. R-1 = 0.0495. The structure of 3 contains centrosymmetric ion quadrupoles [(Me2NH2)(BeCl4)](2)(2-) forming by N-(HCI)-C-... bridges between (Me2NH2)(+) and [BeCl4](2-) ions.