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

Abstract

[Cd(Se-2,4,6-i-Pr(3)-C(6)H(2))(2)(bpy)] (1) has been characterized by X-ray crystallography and studied by solution and solid-state (113)Cd and (77)Se 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) Å, b = 21.43(4) Å, c = 16.72(3) Å, V = 7881.3(4) Å(3), 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 (delta(11) = 752 ppm, delta(22) = 570 ppm, delta(33) = 93 ppm) and (delta(11)= 733 ppm, delta(22) = 547 ppm, delta(33) = 100 ppm) with respect to 0.1 M aq. Cd(ClO(4))(2). Those for selenium are (delta(11) = -950 ppm, delta(22) = -1040 ppm, delta(33) = -1599 ppm) and (delta(11) = -933 ppm, delta(22) = -1069 ppm, delta(33) = -1586 ppm) with respect to solid (NH(4))(2)SeO(4). The orientation of the cadmium chemical shift tensor is similar to that of the previously published sulfur analog.

Solid-state selenium-77 NMR

“…Single-crystal NMR of the cadmium complex Cd(SeC 6 H 2 ( i Pr) 3 ) 2 (bpy), which was investigated as an analogue to biologically occurring metalloproteins that are coordinated by cysteine and histidine residues, provide the orientation of the two selenium chemical shift tensors which are shown in Fig. 11 [197]. A recent example of selenium bridging carbon and cadmium centers occurs in the polymeric N,N 0 -dimethylimidazolidine-2-thione cadmium selenocyanate [(Me 2 Imt)Cd(SeCN) 2 ] 1 [198].…”

Cadmium bis(phenylselenolate) as a precursor for the synthesis of polymeric Cd(μ-Se)clusters: Crystal and molecular structures of [Cd4(SePh)7(PPh3)X] (X = Cl, Br)

“…In this work, we have extended the use of Hg(EPh) 2 (E = Se, Te) [4][5][6][7][8][9][10][11] as a precursor for the preparation of clusters to Cd(SePh) 2 , offering a complementary methodology in the place of silyl reagents [15][16][17][18][19][20]. Because this approach should be extensible to the synthons of the general formula M(ER) n for which a great many examples have been reported [21,22], we predict that a systematic methodology for the synthesis of binary and ternary clusters would be possible.…”

On the search of size- and shape-controlled metal chalcogenide cluster compounds

“…Because this approach should be extensible to the synthons of the general formula M(ER) n , for which the examples M ¼ Mg, Bi, Ga, In, Sn, Sb, Zn, Cd, Hg, Au, Yb, Zr, Hf; E ¼ S, Se, Te; R ¼ aryl, alkyl, have been reported [48,49], we predict that a systematic methodology with basis on Hg-organyltellurolate/selenolate reagents for the synthesis of binary and ternary clusters should be possible.…”