Single-Crystal, Solid-State, and Solution 113Cd and 77Se NMR and X-ray Single-Crystal Study of a [Cd(SeR)2(N-donor)2] Complex

[Cd(Se-2,4,6-i-Pr3-C6H2)2(bpy)] (1) has been characterized by X-ray crystallography and studied by solution and solid-state 113Cd and 77Se NMR to serve as an analog for biologically occurring [M(S-Cys)2(His)2] centers. The unit cell parameters for 1 are as follows:  a = 21.99(2) A, b = 21.43(4) A, c = 16.72(3) A, V = 7881.3(4) A3, Z = 8, orthorhombic space group, Pccn. Two chemically inequivalent cadmiums and seleniums are found per unit cell. The principal values of the cadmium chemical shift tensors are (δ11 = 752 ppm, δ22 = 570 ppm, δ33 = 93 ppm) and (δ11= 733 ppm, δ22 = 547 ppm, δ33 = 100 ppm) with respect to 0.1 M aq. Cd(ClO4)2. Those for selenium are (δ11 = −950 ppm, δ22 = −1040 ppm, δ33 = −1599 ppm) and (δ11 = −933 ppm, δ22 = −1069 ppm, δ33 = −1586 ppm) with respect to solid (NH4)2SeO4. The orientation of the cadmium chemical shift tensor is similar to that of the previously published sulfur analog.