Structural variations and spectroscopic properties of copper(I) complexes with bis(schiff base) ligands

Electrochemical Exploration of Active Cu-Based Atom Transfer Radical Polymerization Catalysis through Ligand Modification

The intersection between Cu-catalyzed atom transfer radical polymerization (ATRP) and organometallic mediated radical polymerization (OMRP) has been recently shown to be a result of competition between the Cu^I and Cu^II complexes of polyamine ligands for the same organic free radical. The tetradentate ligands N,N'-bis-2'-pyridylmethyl-ethane-1,2-diamine (L¹) and N,N'-dimethyl-N,N'-bis-2'-pyridylmethyl-ethane-1,2-diamine (L²) form stable Cu complexes which, depending on their oxidation state, can either liberate or complex organic radicals. Herein, we show that this process may be affected by subtle changes to the ligand system. Switching from a tertiary amine (L²) to a secondary amine (L¹) retains ATRP and OMRP activity through a series of cyclic voltammetry measurements in the presence of the initiator bromoacetonitrile.

Synthesis, X-ray crystal structure, Hirshfeld surface analysis and DFT studies of (E)-N'-(2-bromo-benzyl-idene)-4-methylbenzohydrazide

The title mol-ecule, C15H13BrN2O, displays a trans configuration with respect to the C=N double bond. The dihedral angle between the bromo- and methyl-substituted benzene rings is 16.1 (3)°. In the crystal, mol-ecules are connected by N-H⋯O and weak C-H⋯O hydrogen bonds, forming R 2 1(6) ring motifs and generating chains along the a-axis direction. The optimized structure generated theoretically via density functional theory (DFT) using standard B3LYP functional and 6-311 G(d,p) basis-set calculations renders good support to the experimental data. The HOMO-LUMO behaviour was elucidated to determine the energy gap. The inter-molecular inter-actions were qu-anti-fied and analysed using Hirshfeld surface analysis.

Effects of non covalent interactions in light emitting properties of bis-pyridyl-alkyl-di-imines

Crystallization induced emission is observed for bis-pyridyl-ethyl-di-imine and bis-pyridyl-butyl-di-imine. While in case of bis-pyridyl-di-imines, with no alkyl spacer, the quenching is observed in the solid state.

Crystal structures and spectral properties of two polyoxometalate-based inorganic-organic compounds from silver-azine building blocks with bis-bidentate and tridentate ligands

Two polyoxometalate-based inorganic-organic hybrid compounds constructed from silver(I)-L species and saturated Keggin type polyoxoanion, [Ag2L2(1)]2(SiMo12O40)·1.5DMF·0.5CH3OH⋅H2O 1 and [{Ag4L2(2)(DMF)5}(SiMo12O40)] 2 (L(1) = phenyl 2-pyridyl ketone azine, L(2) = 3-phenyltriazolo[1,5-a]pyridine), have been synthesized and structurally characterized by IR, UV, elemental analysis, XRPD and complete single crystal structure analyses, where the ligands L(1) and L(2) are bis-bidentate and tridentate azines synthesized with the same materials under different conditions. The structure of 1 exhibits a dinuclear double-helicate with [SiMo12O40](4)(-) anions as counter ions, where all of the Ag centers coordinate to bis-bidentate chelating ligands. Compound 2 displays a two-dimensional sheet formed by the Ag-organic infinite chains and the [SiMo12O40](4)(-) alternately arranged in a "rail-like" fashion. The luminescent properties of 1 and 2 in the solid state were investigated.

Assembly of one novel polyoxometalate-based inorganic-organic compound from copper-Schiff base building block: synthesis, crystal structure and spectral properties

A novel copper(II) inorganic-organic hybrid compound [CuL(DMF)(CH(3)OH)](2)(PMo(V)Mo(VI)(11)O(40))·2DMF (L=phenyl 2-pyridyl ketone azine) 1 has been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Cu(II) atom has a distorted square pyramidal environment interconnecting with N(3)O(2) donor set. In solid-state there are three types of C-H···π interactions between adjacent [CuL(DMF)(CH(3)OH)](2+), which generate a two-dimensional (2D) layer. Adjacent 2D layers form porous channels in which polyoxoanions as templates are filled. Simultaneously, the oxygen atoms of polyoxoanion as electron acceptors feather multiple intermolecular hydrogen bonds, through which giving rise to a 3D supramolecular network. The luminescent properties of the compound 1 were investigated in the solid state and in aqueous solution at room temperature, respectively.

catena-Poly[[(triphenyl-phosphane)copper(I)]-di-μ-iodido-[(triphenyl-phosphane)copper(I)]-μ-{1,2-bis-[1-(pyridin-4-yl)ethyl-idene]hydrazine}]

In the title coordination polymer, [Cu₂I₂(C₁₄H₁₄N₄)(C₁₈H₁₅P)₂]_n, the Cu^I atom is coordinated by two I atoms, one P atom and one N atom in a fairly regular tetra­hedral arrangement. A crystallographic inversion centre generates a Cu₂I₂ diamond with a Cu–Cu separation of 3.0120 (5) Å. The complete N,N′-(1-pyridin-4-yl-ethethyl­idene)-hydrazine mol­ecule is also generated by inversion symmetry, and this bridging ligand leads to [011] polymeric chains in the crystal structure.

Fluorescent coordination polymeric gel from tartaric acid-assisted self-assembly

A fluorescent organogel is obtained from the reaction of Zn(OAc)(2) x 2 H(2)O, 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (bpd), and tartaric acid (H(4)tar) in methanol. The gel is proposed to have formed by the cross-linking of linear 1D coordination polymers [Zn(bpd)](n) with tartarate coligand in a highly random fashion which entrapped the solvent molecules through hydrogen-bonding interactions between the tar coligand and solvent molecules. Higher dimensional coordination polymeric structure is proposed for this gel based on the corresponding complexes formed by oxalic and succinic acids. The presence of three components is essential for the gelation. Interestingly, organogelation of the coordination polymer has induced remarkable fluorescence properties in the weakly emissive bpd. Such fluorescence enhancement is attributed to the reduction in nonradiative decay in the aggregated state. The organogel exhibits viscoelastic behavior as evidenced from the rheological studies.

(μ-Pyridine-2-carbaldehyde azine)bis-[bis-(triphenyl-phosphine-κP)copper(I)] bis-(tetra-fluorido-borate) dichloro-methane disolvate

In the centrosymmetric title complex, [Cu(2)(C(12)H(10)N(4))(C(18)H(15)P)(4)](BF(4))(2)·2CH(2)Cl(2), the Cu(I) atom adopts a distorted tetra-hedral geometry, defined by two P atoms from two triphenyl-phosphine ligands and two N atoms from a pyridine-2-carbaldehyde azine ligand. The two Cu atoms are bridged by the centrosymmetric pyridine-2-carbaldehyde azine ligand. The F atoms of the tetra-fluorido-borate anion are disordered over two sites [occupancy factors = 0.68 (5) and 0.32 (5)]. The dichloro-methane solvent mol-ecule is disordered over four sites, with occupancy factors of 0.513 (4), 0.173 (5), 0.141 (5) and 0.173 (5).