Synthesis, spectral (FT-IR, 1H, 13C) studies, and crystal structure of [(2,6-CO2)2C5H3NSnBu2(H2O)]2·CHCl3

Di-n-butyltin(IV) 2,6-pyridinedicarboxylate [(2,6-CO2)2C5H3NSnBu2(H2O)]2·CHCl3, has been synthesized and characterized by elemental analyses, infrared and NMR (1H and 13C) spectroscopy, and single-crystal X-ray diffraction. The title complex crystallizes in the triclinic space group P 1 ‾ $P‾{1}$ ; with a = 9.2330(4), b = 10.4790(5), c = 20.2489(8) Å, α = 89.439(4), β = 87.492(3), γ = 85.888(4)°, V = 1951.96(15) Å3, and Z = 2. In this complex, the 2,6-pyridinedicarboxylate groups are tetradentate, chelating, and bridging ligands for the tin(IV) atoms. NMR spectra showed that the ligands bind to the tin(IV) center in the anionic (COO−) form. In the asymmetric unit of the dimeric complex, the monomer is composed of an n-Bu2Sn unit bonded to one 2,6-pyridinedicarboxylate group through one nitrogen and two oxygen donor atoms. It is also coordinated by a water molecule. In the dimer formed by carboxylate bridging, a trans-heptacoordinated geometry around the tin(IV) atom is established. The chloroform molecule is connected to the dimer by C–H···O contacts. Compound exhibits extended O–H···O and C–H···O hydrogen bonding networks leading to a supramolecular layer topology.

Yttrium germole dianion complexes with Y–Ge bonds

The reactions of dipotassium 3,4-dimethyl-2,5-bis(trimethylsilyl)-germole dianion K2[1] with YCl3 and Cp*YCl2 (Cp* = cyclopentadienyl) in THF at room temperature afforded the dianion salt [(K-cryptand-222)2][1-YCl3] (K22) and the dimeric complex [1-Y-Cp*]2...

THE INTERACTION BETWEEN [Pt(µ-Cl)(Safrole-1H)]2 AND 1,3-DIISOPROPYLBENZIMIDAZOLIUM BROMIDE IN THE PRESENCE OF Ag2O

The interaction of the dimeric complex [Pt(µ-Cl)(Saf)]2 (1) (Saf: deprotonated safrole) with the salt iPr2-bimy·HBr in the presence of Ag2O in acetone solvent was studied. The obtained products were mixed complexes of [PtCl(Saf)(iPr2-bimy)] (2) and [PtBr(Saf)(iPr2-bimy)] (3) with different molar ratio (PI, PII, PIII) depended on the used molar ratio of 1:salt:Ag2O. In the case of this ratio being 1:2:1.1, the mixture PI with 75% for the complex 2 was obtained. When concentration of the salt was increased, the product was PII with the molar ratio of 2 : 3 of 1 : 3. However, when both the salt and Ag2O were increased at the same time, 2 and 3 in PIII had equal molar proportions. The two main factors affecting the 2 : 3 molar ratio are the different solubility of AgCl and AgBr and the different coordinating ability of Cl- and Br- ligands. The structure of 2 and 3 was determined by 1H NMR spectra and single crystal X-ray diffraction. The results reveal that Saf in 2 and 3 coordinates with Pt(II) via C=Colefinic and C5 of benzene ring. Meanwhile, iPr2-bimy coordinates with Pt(II) through CNCN and is in trans-position compared with the C=Colefinic bond.

Synthesis and crystal structure of 1,1′-bis{[4-(pyridin-2-yl)-1,2,3-triazol-1-yl]methyl}ferrocene, and its complexation with CuI

The title compound, [Fe(C13H11N4)2], was synthesized starting from 1,1′-ferrocenedicarboxylic acid in a three-step reaction sequence. The dicarboxylic acid was reduced to 1,1′-ferrocenedimethanol using LiAlH4 and subsequently converted to 1,1′-bis(azidomethyl)ferrocene in the presence of NaN3. The diazide was treated with 2-ethynylpyridine under `click' conditions to give the title compound in 75% yield. The FeII center lies on an inversion center in the crystal. The two pyridyltriazole wings are oriented in an anti conformation and positioned exo from the FeII center. In the solid state, the molecules interact by C—H...N, C—H...π, and π–π interactions. The complexation of the ligand with [Cu(CH3CN)4](PF6) gives a tetranuclear dimeric complex.

Unravelling the Chemistry of the [Cu(4,7-Dichloroquinoline)2Br2]2 Dimeric Complex through Structural Analysis: A Borderline Ligand Field Case

Large dark prismatic crystals (P 1 ¯ ) consisting of closely packed centrosymmetric [Cu(4,7-dichloroquinoline)2]2Br4 binuclear units are formed when 4,7-dichloroquinoline (DCQ, C9H5NCl2) binds copper(II). Cu2+ adopts a strongly distorted square pyramidal coordination geometry, perturbed by electrostatic interactions with two axial μ–Br ligands acting as highly asymmetric bridges. It is shown that, as electronic states of ligands are higher in energy than the metal ones, antibonding orbitals bear significant ligand-like character and electronic charge is partially transferred from inner-sphere coordinated halogen atoms to copper. Overall, the title compound sits on the Hoffman’s border between main group and transition chemistry, with non-negligible contributions of the ligands to the frontier orbitals. The relative energy placement of metal and ligand states determines an internal redox process, where the metal is slightly reduced at the expense of partial oxidation of the bromide ligands. In fact, the crystal structure is partially disordered due to the substitution of some penta-coordinated Cu(II) centers with tetra-coordinated Cu(I) ions. The geometry of the complex is rationalized in terms of electrostatic-driven distortions from an ideal octahedral prototype. Implications on the reactivity of Cu(II)–quinoline complexes are discussed.