Room‐Temperature Synthesis of the Highly Polar Cluster Compound Sn[SnCl][W₃Cl₁₃]

Abstract

Abstract A new synthetic strategy is employed to synthesize a tungsten trinuclear cluster compound with an ionic liquid (IL) as the reaction medium. Dark brown block‐shaped crystals of Sn[SnCl][W 3 Cl 13 ] were obtained at room temperature by reacting tin and WCl 6 in Lewis acidic ionic liquid [BMIM]Cl/AlCl 3 ([BMIM] + = 1‐butyl‐3‐methylimidazolium). Compound Sn[SnCl][W 3 Cl 13 ] crystallizes in the polar hexagonal space group P 6 3 with cell parameters a = 959.8(1) and c = 1190.3(2) pm. The crystallographic point group of the [W 3 (μ 3 ‐Cl)(μ‐Cl) 3 Cl 9 ] 3– cluster anions is C 3 , but C 3 v pseudosymmetry is observed within twice the standard deviation of the bond lengths. The W–W bond length is 272.18(6) pm. The tin(II) cations, which are in trigonal pyramidal and in distorted trigonal‐antiprismatic coordination spheres that comprise chloride ions, connect the clusters into layers that are stacked according to the 6 3 screw axis. One of the chloride ions is bound only to a single tin cation resulting in a [Sn II Cl] + group with a Sn–Cl bond length of 236.1(5) pm. The pronounced polarity of the crystal structure means that its diffraction pattern exhibits huge deviations from Friedel's law. Most remarkable is that the intensity ( F c 2 ) of reflection 004 is 175 % of the intensity of the 00 $\bar {4}$ reflection.