The cadmium(I) ion, Cd2 2+; X-ray crystal structure of Cd2(AlCl4)2

Abstract

The structure of Cd2(AIC14)2 has been determined by X-ray crystallography and the Cd-Cd bond length found to be 2.576 A.Morse and Jones in 1890 first reported that molten CdC12 dissolves a substantial amount of cadmium.' From their melts they obtained black solids of the composition Cd4C17, Cd4Br7, and CdI2Il3 which they claimed contained a CdJ halide as well as the CdII halide. Later, Hollens and Spencer showed that these solids were a mixture of finely divided cadmium and cadmium(rr) halide.' However, from melting point depression studies of solutions of cadmium in cadmium chloride and from the fact that the solutions are diamagnetic, Grjotheim et al. concluded that Cd22+ is formed when cadmium is dissolved in liquid cadmium chloride.3 Their magnetic measurements were in agreement with those of Farquharson and Heymann who also found these solutions to be diamagnetic.4 Grjotheirn et al. concluded that neither the Cd+ ion nor solvated cadmium atoms are present in the melts. The most recent work on CdI salts is due to Corbett and coworkers.5J~They pointed out that

Energy analysis of metal–metal bonding in [RM–MR] (M=Zn, Cd, Hg; R=CH3, SiH3, GeH3, C5H5, C5Me5)

“…For cadmium, the compounds [Cd 2 (AlCl 4 ) 2 ] [7] and [Cd 2 (TpMe 2 ) 2 ] [8] (TpMe 2 = hydrotri(3,5-dimethylpyrazolyl) borate) containing Cd-Cd bonds have been synthesized and characterized. For zinc, compound HZnZnH was previously generated and characterized in matrix isolation experiments [9,10].…”

Molecular Alloys: Experimental and Theoretical Investigations on the Substitution of Zinc by Cadmium and Mercury in the Homologous Series [Mo(M′R)12] and [M(M′R)8] (M=Pd, Pt; M′=Zn, Cd, Hg)

“…It crystallizes in the triclinic space group P1 with two molecules in the unit cell. The single-crystal X-ray structure determination of 3 ( Figure 1) reveals an icosahedral environment of the central molybdenum atom by three ZnCp* and nine CdMe ligands, which is very similar to the structure of [Mo- 9 ]. It should be noted that the differences in electron densities and X-ray scattering power of Zn/Ga versus Cd/Ga and Zn/Cd vary and therefore the Cd atoms can be easily located in solid-state structures.…”

“…The structural properties determined by single-crystal Xray diffraction and the theoretical bonding analysis of a selection of prototypes of the series-for example, the icosahedral molecule [MoA C H T U N G T R E N N U N G (ZnCp*) 3 A C H T U N G T R E N N U N G (ZnMe) 9 ] or the slightly distorted trigonal dodecahedral molecule [PdA C H T U N G T R E N N U N G (ZnCp*) 4 …”

“…The comparably stable Cd 2 2 + ion exhibits a much stronger covalent CdÀCd s bond and consequently shows a quite close CdÀCd contact (e.g., 2.576 in [Cd 2 A C H T U N G T R E N N U N G (AlCl 4 ) 2 ]). [9] The 1 H NMR spectrum of 1 at room temperature in C 6 D 6 is very simple and gives rise to only two singlets at d = 0.03 ppm (12 Pt and 113 Cd NMR spectroscopic studies turned out to be difficult because of the instability of 1 in solution and will be presented elsewhere.…”

SnAl2OCl6, ein quaternäres Oxidchlorid mit kantenverknüpften [Al4O2Cl10]-Tetrameren und [(SnCl2/2Cl5)2]-Dimeren

“…Das Anion [AlCl 4 ] ± tritt nicht nur in Tetrachloroaluminaten(III) mit Alkalimetall-oder verwandten einwertigen Gegenionen (NH 4 + , Ga + , In + , Tl + , Ag + , Cu + ) auf [1], es eignet sich auch zur ¹Stabilisierungª ungewo È hnlicher Kationen wie [Hg 3 ] 2+ in Hg 3 [AlCl 4 ] 2 [2] oder [Cd 2 ] 2+ in Cd 2 [AlCl 4 ] 2 [3,4]. Auch mit zweiwertigen Gegenkationen liegen Untersuchungen vor; die Chloride M II (AlCl 4 ) 2 (M = Co, Cu, Pd, Sm u.…”