The reactions of gallium subhalides Ga₂X₄·2dioxane (X = Cl, Br) and “GaI” with carbonylmetallates of chromium, iron and cobalt result in the formation of various gallium halide complexes. These are [(CO)₅CrGaBr(thf)₂] (6), with a terminal GaX unit, and [(CO)₄FeGaCl(thf)]₂ (1), [(CO)₄FeGaCl₂Na(thf)₂]_x (2), [(CO)₄FeGaI₂Na(thf)₃]₂ (4) and [Cr₂(CO)₈(GaI₂)INa₂(thf)₇]_x (8) with GaX units in the bridging positions of gallium–transition-metal rings. In addition, mixed cyclic gallium–iron hydroxides [{(CO)₄Fe}₂Ga₄Cl₅(OH)₃(thf)] 3 and 4 and gallium oxo/hydroxo cages 5, 9 and 10 were observed. Rings of [{GaCo₄(CO)₁₄}K(thf)]₆ (11), prepared from Ga₄Cl₄R₄ [R = Si(SiMe₃)₃] and K[Co(CO)₄], are connected through isocarbonyl–potassium interactions to form channels. All compounds were characterized spectroscopically and by X-ray crystallography. DFT calculations were performed on cobalt–gallium complexes to evaluate their bonding properties.

On reaction of BiBr₃ with Li(thf)₃SiPh₂tBu (1) in the corresponding ratios redox/metathesis reactions were observed, yielding dibismuthane (tBuPh₂Si)₄Bi₂ (2) and disilylbismuth halide (tBuPh₂Si)₂BiBr (3). The latter is a reaction intermediate in the formation of the dark-red 2. The X-ray crystal structures of 1–3 were determined by low-temperature X-ray diffraction. The Si₂Bi–BiSi₂ core of 2 is in the semi-eclipsed conformation. No oligomerization of “nonthermochromic” 2 was observed. Compound 3 is a mixed substituted monomer with a pyramidal environment around the bismuth center. On the basis of quantum chemical calculations, the formation of tertiary bismuthane (tBuPh₂Si)₃Bi is not expected for steric reasons. According to DFT-optimized geometries of the simplified model systems n[(H₃Si)₂Bi]₂ (n = 1–3), the closed-shell attraction between intermolecular Bi centers in the chain provides a moderate elongation of the intramolecular Bi–Bi bond in the dibismuthane unit and a shortening of the intermolecular Bi···Bi contacts. According to MP4(SDQ) computations, such oligomerization is carried out by intermolecular interaction of s lone pairs that are bound together and p-type orbitals of the Bi–Bi bonds in the bismuth chain. An increase in the number of [(H₃Si)₂Bi]₂ molecules per chain results in a decrease in the HOMO–LUMO gap and leads to a bathochromic shift. TD-PBE0 computations suggest that the lowest energy electron transition in 2 is metal–metal charge transfer. In addition, the attractive contributions in the chain [(H₃A)₂Bi]₂···[Bi(AH₃)₂]₂ with silyl groups (A = Si) outweigh the repulsion of the Bi···Bi centers, whereas for the alkyl-substituted bismuth chain (A = C) the repulsive van der Waals force dominates. This fact makes the rectangle oligomerization model more preferred for n[(H₃A)₂Bi]₂ (A = C; n = 2), while for A = Si chain formation is favored in the gas phase.

The reaction of cyclo-Bi₄[Si(SiMe₃)₃]₄ (1) with Na₂[Fe(CO)₄] in the presence of nBu₄NCl leads to the formation of the cage compound [nBu₄N]₄[Bi₄Fe₈(CO)₂₈] (2). According to X-ray single-crystal structure analysis, the faces of the tetrahedral Bi₄ core are capped by Fe(CO)₃ moieties in a μ₃ fashion to give a cubanoid Bi₄Fe₄ framework. The four Fe(CO)₄ fragments are μ₁-coordinated to bismuth, each. With 12 skeletal electron pairs the [Bi₄Fe₈(CO)₂₈]^4– anion (2a) is a Bi₄Fe₄ cubane. The negative charge is localized within cluster 2a according to the NBO analysis of its derivatives. The strength of metal–ligand interactions Bi–μ₃-Fe(CO)₃ is responsible for the size of the cluster's cubic core. NICS computations at the cage centers of considered molecules show that 2a has paratropic character, whereas removal of four μ₁-Fe(CO)₄ fragments from latter causes spherical aromaticity of the modified clusters [Bi₄Fe₄(CO)₁₂]^4– (2aa) and [Bi₄Fe₄(CO)₁₂]²⁺ (2ab), mediated by a Bi₄ cluster π orbital.

The gallium(I) derivative [Ga({N(dipp)CMe}₂CH)] (1; dipp=2,6-diisopropylphenyl) undergoes facile oxidative addition reactions with various element–hydrogen bonds including NH, PH, OH, SnH, and HH bonds. This was demonstrated by its reaction with triphenyltin hydride, ethanol, water, diethylamine, diphenylphosphane, and dihydrogen. All products were characterized by means of single-crystal X-ray structure determination, NMR spectroscopy, IR spectroscopy, and mass spectrometry.

The oxidation of the hexacarbonyl(1,3-dithiolato-S,S′)diiron complexes 4a–4c with varying amounts of dimethyldioxirane (DMD) was systematically studied. The chemoselectivity of the oxidation products depended upon the substituent R (R=H, Me, 1/2 (CH₂)₅). For R=H, four oxidation products, 6a–6d, have been obtained. In the case of R=Me, three products, 7a–7c, were formed, and for R=1/2 (CH₂)₅, only complex 8 was observed. These observations are due to steric and electronic effects caused by the substituent R. Additionally, oxidation of the triiron complex 5 with DMD was performed to yield the products 9a and 9b. X-Ray diffraction analyses were performed for 6a–6d, 7a, and 7c, as well as for 9a and 9b. The electronic properties were determined by density-functional theory (DFT) calculations.