Structure and Reactivity of 1,8-Bis(naphthalenediyl)dipnictanes

Syntheses and solid-state structures of diarsane Naph2As2 (Naph = 1,8-naphthalenediyl, 1) and (Naph)5Sb4Cl2 3 are reported and the σ-donor capacity of Naph2E2 (E = As 1, Sb 2) was studied in reactions with (coe)Cr(CO)5 (coe = Z-cyclooctene), yielding [Naph2As2][Cr(CO)5]2 (4) and [Naph2E2][Cr(CO)5] (E = As 5, Sb 6). In contrast, reactions of 1 and 3 with Me2SAuCl proceed with oxidation and formation of elemental gold as well as Naph2(AsCl)2 (7) and [NaphSbCl2]2 8. All complexes were characterized by elemental analyses, heteronuclear (1H, 13C) NMR and FT-IR spectroscopy, as well as single crystal X-ray diffraction. Intermolecular E···π interactions (E = As, Sb), which were observed in 7 and 8, were quantified by use of density functional theory and local coupled cluster electronic structure theory calculations. These allow to assess the nature and relative importance of covalent and noncovalent interactions and illustrate how dispersion interactions change with the electronic structure of the compounds

Formation and Cleavage of a Sb−Sb Double Bond: From Carbene-Coordinated Distibenes to Stibinidenes

Stibine [L(Cl)Ga]2SbCl reacts with N-heterocyclic carbenes RNHCMe to either RNHCMe-coordinated distibenes L(Cl)Ga]SbSb(RNHCMe)Ga(Cl)L ((RNHCMe=Me, Et, i-Pr) or stibinidenes L(Cl)GaSb-RNHCMe (RNHCMe=Me, Et) after Sb−Sb bond cleavage. Energies of the products and possible reaction intermediates were calculated by DFT methods

Redox Activity of Noninnocent 2,2 '-Bipyridine in Zinc Complexes: An Experimental and Theoretical Study

[Image: see text] We report on a systematical reactivity study of β-diketiminate zinc complexes with redox-active 2,2′-bipyridine (bpy). The reaction of LZnI (L = HC[C(Me)N(2,6-iPr(2)C(6)H(3))](2)) with NaB(C(6)F(5))(4) in the presence of bpy yielded [LZn(bpy)][B(C(6)F(5))(4)] (1), with bpy serving as a neutral ligand, whereas reduction reactions of LZnI with 1 or 2 equiv of KC(8) in the presence of bpy gave the radical complex LZn(bpy) (2) and [2.2.2-Cryptand-K][LZn(bpy)] (3), in which bpy either acts as a π-radical anion or a diamagnetic dianion, respectively. The paramagnetic nature of 2 was confirmed via solution magnetic susceptibility measurements, and UV–vis spectroscopy shows that 2 exhibits absorption bands typical for bpy radical species. The EPR spectra of 2 and its deuterated analog 2-d(8) demonstrate that the spin density is localized to the bpy ligand. Density functional theoretical calculations and natural bond orbital analysis were employed to elucidate the electronic structure of complexes 1–3 and accurately reproduced the structural experimental data. It is shown that reduction of the bpy moiety results in a decrease in the β-diketiminate co-ligand bite angle and elongation of the Zn–N(β-diketiminate) bonds, which act cooperatively and in synergy with the bpy ligand by decreasing Zn–N(bpy) bond lengths to stabilize the energy of the LUMO

Comparing London dispersion pnictogen–π interactions in naphthyl-substituted dipnictanes

Using a combination of NMR, single crystal X-ray diffraction (sc-XRD) and quantum chemistry, the structure-directing role of London Dispersion (LD) is demonstrated for dibismuthane Bi2Naph2 (1). 1 shows intermolecular Bi⋯π contacts in the solid-state, while π⋯π interactions as observed in the lighter homologues are missing. Comparison of the whole series of dipnictanes revealed the influence of the pnictogen atom on the strength of London dispersion and highlights its importance in heavy main group element chemistry