The Hexacyanotitanate Ion: Synthesis and Crystal Structure of [NEt4]3[TiIII(CN)6]·4MeCN

The hexacyanotitanate salt, [Et 4 N] 3 [Ti(CN) 6 ]·4MeCN, has been prepared by addition of tetraethylammonium cyanide to the titanium(III) triflate salt Ti(O 3 SCF 3 ) 3 (MeCN) 3 . The orange crystalline product has been characterized by X-ray diffraction, and the d 1 anion is only slightly distorted from ideal O h symmetry. The anion resides on a center of symmetry and is characterized by the following parameters: Ti−C = 2.195(2), 2.197(3), and 2.213(3) Å; C−N (av) = 1.141(4) Å; C−Ti−C (cis) = 88.01(9), 88.02(9), 89.02(9), and 89.78(9)°; C−Ti−C (trans) = 180°. In addition to the crystallographic study, details of the IR (ν CN = 2071 cm - 1 ), EPR, and UV−vis spectra (Δ o = 22800 cm - 1 ) are given. Crystal data for [Et 4 N] 3 [Ti(CN) 6 ]·4MeCN are as follows: monoclinic, space group I 2/ a, a = 18.171(6) Å, b = 12.200(4) Å, c = 20.989(5) Å, β = 91.17(2)°, V = 4652(2) Å 3, Z = 4, wR 2 = 0.2054 for 3831 data, 27 restraints, and 318 parameters.