A neutral Pt3 stack unsupported by any bridging ligand

Pt···Pt···Pt interactions via their d(8) orbitals, combined with π-π stacking of deprotonated, chelating 2-(3'-pyrazolyl)pyridine (pyzpy) ligands, are responsible for trans-Pt(pyzpy)(2) (2) crystallization in a stack of three molecules unsupported by any bridging ligand.     

A new ruthenium(II) hydride carbonyl complex with pyrimidine ligand

The reaction of [RuHCl(CO)(PPh₃)₃] with pyrimidine gives [RuHCl(CO)(PPh₃)₂(C₄H₄N₂)]. The compound has been studied by IR, UV-Vis and X-ray crystallography. The molecular orbital diagram of the complex has been calculated with density functional theory (DFT). The spin-allowed singlet-singlet electronic transitions of the complex have been calculated with time-dependent DFT method, and the UV-Vis spectrum of the compound has been discussed on this basis. Emission of the compound was studied.     

Reactivity of an aluminum hydride complex with a redox-active diimine ligand

Russian Chemical Bulletin - The reaction of the hydride [(dpp-bian)Al(H)Cl] (1) containing the 1,2-bis[(2,6-diisopropylphenyl) imino]acenaphthene (dpp-bian) radical anion with MeLi affords the...     

A diketiminate‐bound diiron complex with a bridging carbonate ligand

Reduction of carbon dioxide by a diiron(I) complex gives μ‐carbonato‐κ³O:O′,O′′‐bis{[2,2,6,6‐tetramethyl‐3,5‐bis(2,4,6‐triisopropylphenyl)heptane‐2,5‐diiminate(1−)‐κ²N,N′]iron(II)} toluene disolvate, [Fe₂(C₄₁H₆₅N)₂(CO₃)]·2C₇H₈, a diiron(II) species with a bridging carbonate ligand. The asymmetric unit contains one diiron complex and two cocrystallized toluene solvent molecules that are distributed over three sites, one with atoms in general positions and two in crystallographic sites. Both Fe^II atoms are η²‐coordinated to diketiminate ligands, but η¹‐ and η²‐coordinated to the bridging carbonate ligand. Thus, one Fe^II center is three‐coordinate and the other is four‐coordinate. The bridging carbonate ligand is nearly perpendicular to the iron–diketiminate plane of the four‐coordinate Fe^II center and parallel to the plane of the three‐coordinate Fe^II center.     

A binuclear tantalum(III) complex with a bridging carboxylato ligand

Ta₂Cl₆(SMe₂)₃ reacts with one equivalent of C₄H₉CO₂Li to give a complex with a bridging carboxylate ligand, Ta₂Cl₅(O₂CC₄H₉)(SMe₂)(THF)₂. The product was isolated in two crystalline forms, 1 and 2, from a THF/hexane and benzene/hexane solvent mixture, respectively. The following are the unit cell parameters, for 1: monoclinic (P2₁/n), a = 10.537(5) Å, b = 22.015(4) Å, c = 11.663(4) Å, β = 107.80(3)°, V = 2576(3) ų, and Z = 4; for 2: monoclinic (P2₁/c), a = 15.584(4) Å, b = 15.647(4) Å, c = 11.275(3) Å, β = 106.04(5)°, V = 2642(3) ų and Z = 4. The complex is a dimer with a distorted octahedra-sharing-an-edge geometry. The TaTa distances in 1 and 2 were 2.766(1) Å and 2.779(1) Å, respectively, which is somewhat longer than in previously reported Nb(III) and Ta(III) dinuclear compounds. Diamagnetism of the complex is shown by NMR. Fenske—Hall calculations, which correctly predict an electronic transition at about 16,000 cm^?1, indicate a double TaTa bond. The observed elongation of the metalmetal bond is attributed mainly to steric crowding. The complex is the first proven low-valent Ta species with a coordinated carboxylate ion.     

A donor--acceptor--donor bridging ligand in a class III mixed-valence complex

The novel mononuclear and dinuclear complexes [Ru(trpy)(bpy)(apc)][PF(6)] and [(Ru(trpy)(bpy))(2)(mu-adpc)][PF(6)](2) (bpy = 2,2'-bipyridine, trpy = 2,2':6',2' '-terpyridine, apc(-) = 4-azo(phenylcyanamido)benzene, and adpc(2)(-) = 4,4'-azodi(phenylcyanamido)) were synthesized and characterized by (1)H NMR, UV-vis, and cyclic voltammetry. Crystallography showed that the dinuclear Ru(II) complex crystallizes from diethyl ether/acetonitrile solution as [(Ru(trpy)(bpy))(2)(mu-adpc)][PF(6)](2).2(acetonitrile).2(diethyl ether). Crystal structure data are as follows: crystal system triclinic, space group P1, with a, b, and c = 12.480(2), 13.090(3) and 14.147(3) A, respectively, alpha, beta, and gamma = 79.792(3), 68.027(3), and 64.447(3) degrees, respectively, V = 1933.3(6) A(3), and Z = 1. The structure was refined to a final R factor of 0.0421. The mixed-valence complex with metal ions, separated by a through-space distance of 19.5 A, is a class III system, having the comproportionation constant K(c) = 1.3 x 10(13) and an intervalence band at 1920 nm (epsilon(max) = 10 000 M(-1) cm(-1)), in dimethylformamide solution. The results of this study strongly suggest that the bridging ligand adpc(2-) can mediate metal-metal coupling through both hole-transfer and electron-transfer superexchange mechanisms.     

A carbonyl-rich bridging hydride complex relevant to the Fe-Fe hydrogenase active site

Protonation of Fe(2)(μ-S(2)C(3)H(6))(CO)(6) with an acid derived from [SiEt(3)][B(C(6)F(5))(4)] and HCl affords a hydride-bridged dimer.     

Formation of a tetranuclear nickel(ii) complex containing an unusual bridging ligand

Russian Chemical Bulletin -     

A new ruthenium complex with an electron-donating aminoindenyl ligand for fast metal-mediated living radical polymerizations

A new ruthenium complex with an electron-donating aminoindenyl ligand induces a fast living radical polymerization of methyl methacrylate (MMA) in the presence of a chloride initiator to give polymers with controlled and variable molecular weights (Mn = 103-105) and very narrow molecular weight distributions (Mw/Mn < 1.1). The structure and high activity of the catalyst were analyzed by X-ray crystallography and cyclic voltammetry in comparison to those of a similar complex with an indenyl ligand.     

Stacking interaction in crystals of a dinuclear rhodium complex with a bridging phenylborole ligand

Russian Chemical Bulletin -     

A new ligand and its complex with multi-stimuli-responsive and aggregation-induced emission effects

A new ligand containing tetraphenylethylene and terpyridine moieties, and its zinc ion complex were synthesized. Both of them exhibit an aggregation-induced emission effect. Their colors and emissions can be smartly switched by various external stimuli including grinding, heating and solvent-fuming, as well as exposure to acid and base vapors.     

Efficient synthesis of a new ditopic bipyridine–terpyridine bridging ligand

Abstract

The novel bipyridine–terpyridine–phenazine ligand 6-pyrid-(tetrapyrido[2,3-a:2′,3′-c:3′′,2′′-h:2′′′,3′′′-j]phenazine (I) was prepared by condensation reaction of 5,6-diamino-l,10-phenanthroline (4) and 2-(pyrid-2′-yl)-1,10-phenanthroline-5,6-dione (6) and characterized using conventional methods. Poor solubility of the ligand led us to the preparation of its Ru(II) complexes to investigate the change in its solubility for further characterizing the ligand on the metal ion. [Ru(ttp)(I)](PF₆)₂ complex was prepared using the reaction of the ligand (I) and [Ru(ttp)Cl₃] complex, where ttp is 4′-(4-Methylphenyl)-2,2′:6′,2′′-terpyridine. A different route for the preparation of [Ru(ttp)(I)](PF₆)₂ was introduced. Synthesis of the ligand (I) on the complex by a condensation reaction of [Ru(ttp)(6)](PF₆)₂, where ligand (6) is 2-(pyrid-2′-yl)-1,10-phenanthroline-5,6-dione, with 5,6-diamino-l,10-phenanthroline (4) was conducted. The spectroscopic measurements of both products which have been obtained through the two different routes were compared. We observed that the NMR, LC-MS, and UV spectra of the both products were identical.     

Dicationic triple-decker complexes with a bridging boratabenzene ligand

New dicationic triple-decker complexes with a bridging boratabenzene ligand [Cp*Fe(μ-η:η-C₅H₅BMe)ML]X₂ (ML=CoCp*, 6(CF₃SO₃)₂; RhCp, 7(BF₄)₂; IrCp, 8(CF₃SO₃)₂; Ru(η-C₆H₆), 9(CF₃SO₃)₂; Ru(η-C₆H₃Me₃-1,3,5), 10(CF₃SO₃)₂; Ru(η-C₆Me₆), 11(CF₃SO₃)₂) were synthesized by stacking reactions of Cp*Fe(η-C₅H₅BMe) (2) with the corresponding half-sandwich fragments [ML]²⁺. The structure of 10(CF₃SO₃)₂ was determined by X-ray diffraction study.     

Some new rhodium(I)-iridium(III) complexes with bridging hydride and chloride ligands

[IrH₅(PEt₃)₂] reacts with [(PR₃)₂Rh(μ₂-Cl)₂(PR₃)₂] (PR₃ = PEt₃ or 2 PR₃ = Ph₂PCH₂CH₂PPh₂) to give the hydrido-bridged binuclear species [(PR₃)₂Rh(μ₂-H)(μ₂-Cl)IrH₂(PR₃)₂] which show catalytic activity in alkene hydrogenation.