Synthesen und Kristallstrukturen von [PPh3Me]NO2 und [PPh3 Me]HCO2H2O / Syntheses and Crystal Structures of [PPh3Me]NO2 and [PPh3Me]HCO2H2O

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh₃Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh₃Me]NO₂ (1) forms pale yellow crystals, and [PPh₃Me]HCO₂·H₂O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh₃Me]HCO₂·2H₂O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh₃Me]NO₂ (1): space group P2₁/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh₃Me⁺ ions and NO²⁻ anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh₃Me]HCO₂·H₂O (2): space group P2₁/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh₃Me⁺ ions and formate anions which form centrosymmetric dimeric units [HCO₂·H₂O]₂²⁻ through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.