Vapor-triggered Reversible Crystal Transformation in Nickel-based Magnetic Molecular Switch

Vapor-trigged crystal to crystal transformation between a discrete trinuclear complex [Ni3(sih)2(py)8] and a two-dimensional (2D) coordination polymer [Ni3(sih)2(py)2]n·DMF·H2O was demonstrated. It provides an example of solid-state coordination induced spin state...

Molecular and Supramolecular Structures of Cd(II) Complexes with Hydralazine-Based Ligands; A New Example for Cyclization of Hydrazonophthalazine to Triazolophthalazine

Molecular and supramolecular structures of two polymeric and one trinuclear Cd(II) complex with hydralazine-type ligands were presented. Self-assembly of E-1-(2-(thiophen-2-ylmethylene)hydrazinyl)phthalazine (HL) and CdCl2 gave the 1D coordination polymer [Cd(H2L)Cl3]n*H2O, 1, in which the Cd(II) ion is hexa-coordinated with one cationic monodentate ligand (H2L+) and five chloride ions, two of them acting as connectors between Cd(II) centers, leading to the formation of a 1D coordination polymer along the a-direction. Using DFT calculations, the cationic ligand (H2L+) could be described as a protonated HL with an extra proton at the hydrazone moiety. Repeating the same reaction by heating under reflux conditions in the presence of 1 mL saturated aqueous KSCN solution, the ligand HL underwent cyclization to the corresponding [1,2,4]triazolo[3,4-a]phthalazine-3(2H)-thione (TPT) followed by the formation of [Cd(TPT)(SCN)2]n*H2O, 2, a 1D coordination polymer. In this complex, the Cd(II) is coordinated with one NS-donor TPT bidentate chelate and two bridged μ(1,3)-thiocyanate ions connecting the Cd(II) centers forming the 1D polymer array along the b-direction. Heating E-2-(1-(2-(phthalazin-1-yl)hydrazono)ethyl)phenol HLOH with CdCl2 under reflux condition gave the trinuclear complex [Cd3(Hydralazine)2(H2O)2Cl6], 3, indicating the hydrolysis of the hydrazonophthalazine ligand HLOH during the course of the reaction. Due to symmetry considerations, there are only two different Cd(II) centers having CdN2Cl3O and CdN2Cl4 coordination environments. Hirshfeld topology analysis was used to analyze the solid-state supramolecular structure of the studied complexes.

A Photoluminescent Au(I)/Ag(I)/PNN coordination complex for Relatively Rapid and Reversible Alcohol Sensing

Trinuclear complex [Au2Ag(dppmaphen)2(CN)2]PF6 photoluminesces on exposure to low molecular weight alcohols. This emission is likely due to C-H···π interactions between the analyte and –PPh2 group, that inhibits non-radiative relaxation of...

Isolation and Studies of Thioether-functionalized Pyrazole Derived Cu(I)-based Cyclic Trinuclear Complex and Its Coordination Polymers with [Cu2I2] and [BiBr3] Nodes

Cu(I)-based cyclic trinuclear complexes (CTCs) represent one of the most intensively investigated candidates in coinage metal-derived CTCs because of their rich photoluminescent properties. Beyond molecular level, coordination polymers built upon...

A Linear Metal-Metal Bonded Tri-Iron Single-Molecule Magnet

The linear trinuclear complex cation [Fe3(DpyF)4]2+ was prepared as [Fe3(DpyF)4](BF4)2·2CH3CN. With large Fe–Fe distances of 2.78 Å, this complex demonstrates intramolecular ferromagnetic coupling between the anisotropic FeII centers (J/kB =...

A hybrid bioinspired catechol-alloxazine triangular nickel complex stabilizing protons and electrons

We report the design of a unique bioinspired ligand merging redox-active catechol and flavin-related alloxazine substructures. Upon coordination with a Ni(II) salt, this hybrid ligand forms a trinuclear complex containing...

A theoretical insight on the anion···anion interactions observed in the solid state structure of a herero-trinuclear complex

A heteronuclear cobalt(III)/potassium complex, [(L1)2Co2K(L2)2], {Where, H2L1 = N,N-bis(3-ethoxysalicylidene)2,2-dimethyl-1,3-propanediamine and HL2 = 3-ethoxysalicylaldehyde}, has been synthesized and characterized by several analytical techniques including single crystal X-ray diffraction analysis. The energetic...

Interconversion between square-planar palladium(II) and octahedral palladium(IV) centres in a sulfur-bridged trinuclear structure

Treatment of fac-[Rh(apt)3] (apt = 3-aminopropanethiolate) with Pd2+ gives an S-bridged trinuclear complex, [Pd{Rh(apt)3}2]4+ ([1]4+), which is interconvertible with [Pd{Rh(apt)3}2]2+ ([2]2+). This interconversion is accompanied by a drastic change between...

Microwave Assisted Synthesis and Characterisation of Trinuclear Zinc(II) Schiff Base Complexes Derived from m-phenylenediamine and Salicylaldehyde

A series of Schiff base ligand, SALMPD, and its mono- and trinuclear Zn(II) metal complexes were synthesised from m-phenylenediamine and salicylaldehyde in alcoholic solution. The synthesis of ligand and mononuclear complex were synthesised using conventional condensation method, while the trinuclear complex was done using microwave-assisted synthesis method. The structure of each compound was elucidated by elemental analysis, infrared and 1H NMR spectroscopy. The infrared spectrum of SALMPD shows a strong azomethine (C=N) band at 1621.62cm-1, indicates the formation of the ligand. Upon complexation of the mononuclear complex, the C=N infrared band shifted and the disappearing of the phenolic hydrogen signal in 1H NMR suggesting the chelation between Zinc(II) metal ion and ligand took place when azomethine and phenolic hydrogen deprotonated. The trinuclear complex, Zn3(SALMPD) obtained was consist of two moieties of mononuclear Zn(SALMPD), which act as ligands that chelating to the third Zn(II) metal ion through oxygen atom due to the shifting of M-O infrared band from 575.12-540.53cm-1, which serves as a coordination site for the metal ion.

Intermolecular interaction energies and magnetic properties of spin-isolated multinuclear CuII complexes

Dinuclear CuII complexes with 3,5-dinitrobenzoates and 2,2′-bipyridine (2) or 1,10-phenanthroline (3) were synthesized and characterized. A complete energy framework analysis using the HF/3-21G energy model was performed which found that dispersion forces and C—H...O interactions are responsible for the crystal structure features. The magnetic properties of the complexes show a weak magnetic exchange between spins, resulting in low exchange constants of −2.72 (1) cm−1 and −1.10 (1) cm−1 for complexes (2) and (3), respectively. This results from the low overlap between magnetic orbitals induced by 3,5-dinitrobenzoate bridges and the arrangement of the magnetic orbitals. Consequently, the dinuclear complexes (2) and (3) behave as spin-isolated multinuclear CuII species in contrast to the trinuclear complex with similar ligands.