Synthesis and Characterization of Novel Oxo-Centered Phosphanylzincates of Potassium and Cesium with a Central Zn₆O₂P₄ Double-Heterocubane Cage

Abstract

The hydrolysis reaction of K(2)(MeZn)(2)(PSitBu(3))(2) in THF/toluene solution yields the [(MeZn)(4)Zn(2)(mu(3)-PSitBu(3))(4)(mu(4)-O)(2)](4-) anions independent of the applied stoichiometry. If the applied molar ratio resembles the composition of the anion, [(thf)K](2)[(eta(6)-toluene)K](2)[(MeZn)(4)Zn(2)(mu(3)-PSitBu(3))(4)(mu(4)-O)(2)] (1) crystallizes from a mixture of THF and toluene. In the case with less water, a phosphanediylzincate moiety is bonded to this anion, and [Zn(PSitBu(3))(2)K(4)(thf)(6)](2)[(MeZn)(4)Zn(2)(mu(3)-PSitBu(3))(4)(mu(4)-O)(2)] (2) crystallizes. However, again the major product is 1. The same anion is also observed with larger and softer cations, and [(thf)(3)Cs(2)](2)[(MeZn)(4)Zn(2)(mu(3)-PSitBu(3))(4)(mu(4)-O)(2)] (3) is obtained if the cesium zincate is used in this reaction. In all of these compounds, the anion is a slightly distorted Zn(6)O(2)P(4) double-heterocubane cage with a central Zn(2)O(2) ring having Zn-O bond lengths of approximately 207 pm.

Assembly of ethylzincate compounds into supramolecular structures

“…The compound showing most similarities with 2 is [Ba 2 Zn 4 (Me) 2 (O) (PSiMe 3 ) 4 (thf) 6 ] (Fig. 5), isolated and characterised by Westerhausen and co-workers [41]. The two compounds share the M 2 Zn 4 (m 6 -O) core with the two M atoms in a trans-arrangement, but apart from this core, the two structures are quite different.…”

“…One complex displays a Li 4 Zn 2 (m 6 -O) core with two zinc atoms in a cis-arrangement [38] and one complex a fac-Li 3 Zn 3 (m 6 -O) core [39]. There are three complexes displaying double-cubane cores comprising K 2 Zn 4 (m 6 -O) and Cs 2 Zn 4 (m 6 -O) motifs [40]. These are quite dissimilar to 2, having the two alkali metal ions in a cis-configuration, for example.…”

Recent developments in the field of organic heterobimetallic compounds of the alkaline-earth metals

“…The reaction of this compound, which contains a barium-bound bis(trimethylsilyl)amido group and the activated bridging alkyl substituent, with another equivalent of alkylzinc tri(tert-butyl)silylphosphanide yielded [(thf) 2 Ba 2 Zn 2 (RZn) 4 (PSitBu 3 ) 6 ] with a central Ba 2 P 2 ring. 84 An easy access to phosphanylzincates is also possible via the transmetallation reaction of zinc in alkylzinc phosphanides with the alkaline-earth metals. Surprisingly, dimeric methylzinc tri(tert-butyl)silylphosphanide crystallizes as a tetrameric molecule, however, in solution it dissociates into the dimer again.…”

Crystal structure of a mixed-ligand dinuclear Ba—Zn complex with 2-methoxyethanol having triphenylacetate and chloride bridges

“…There are only a few compounds containing both of these metals and only one is a dimeric structure, with a distance between the atoms of 3.629 (2) Å , significantly shorter than in the title complex [3.9335 (11) Å ], but zinc and barium are connected only via bridging oxygen atoms ( 2 -O) from organic ligands (Van Veggel et al, 1989). Also, in other structures without carboxylate bridges, the ZnÁ Á ÁBa distances are often much shorter than in the title complex with values in the range 3.4325 (5) to 4.850 (3) Å (Westerhausen et al, 2001(Westerhausen et al, , 2006Baggio et al, 2004;John et al, 2008). In those cases where the oxygen atom ( 2 -O) and also carboxylates connect zinc and barium, the ZnÁ Á ÁBa distance is not longer than 3.638 (1) Å (Akine et al, 2006(Akine et al, , 2009(Akine et al, , 2010.…”