Synthesized Coordination Compounds Research Articles

Red and Blue Compounds Formed from Copper(II) Bromide and the Ligand 7-Isobutyl-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine: Synthesis, Spectroscopy and Single-Crystal Structures

Two newly synthesized coordination compounds copper(II) bromide with the ligand 7-isobutyl-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine (abbreviated as ibmtp) are presented, together with their 3D crystal structure and spectroscopic and magnetic properties. The compounds are CuBr2(ibmtp)2 (1) (red crystals) and [CuBr(ibmtp)4]Br(H2O)3 (2) (blue crystals). In (1) the Cu(ii) ion is present in a distorted tetrahedral environment, while in (2) the Cu(ii) ion has a square pyramidal geometry. These crystal structures are also the first ones reported with the ligand ibmtp. Coordination compounds CuBr2(ibmtp)2 (red) and [CuBr(ibmtp)4]Br(H2O)3 (blue), with ibmtp = 7-isobutyl-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine are presented. The Cu(II) is present in distorted tetrahedral, and square pyramidal geometries, respectively, and binds at N3.

Syntheses, crystal, and molecular structures of Mn(II), Zn(II), and Ce(III) compounds and solution studies of Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Ce(III) compounds obtained from a suitable proton transfer compound containing bda and pydcH2 (bda = butane-1,4-diamine; pydcH2 = pyridine-2,6-dicarboxylic acid)

Three new metal–organic compounds formulated as (H2bda)[Mn(pydc)2]·3H2O (1), (H2bda)[Zn(pydc)2]·3H2O (2), and (H2bda)3[Ce(pydc)3]2·4H2O (3) have been synthesized and structurally characterized by elemental analyses, IR, 1H and 13C NMR spectroscopies, and single crystal X-ray diffraction method. The asymmetric units of 1 and 2 contain three water molecules where in both compounds the corresponding metallic center is six-coordinated by two N and four O atoms as a distorted octahedral. The asymmetric unit of 3 contains four water molecules and the Ce(III) atom is nine-coordinated by three N and six O atoms in a distorted tricapped trigonal prism that the N atoms capping the faces. In the crystalline network of these three coordination compounds, hydrogen bonds, π–π stacking, and ion pairing play basic roles in the formation of supramolecular structures, in which they seem to be effective factor in the stabilization of the structure. The protonation constants of bda and pydcH2 and the (H2bda)(pydc) proton transfer equilibrium constants, the stoichiometry and stability of complexes of above mentioned ion pair with Mn2+, Ni2+, Cu2+, Zn2+, Cd2+, and Ce3+ metal ions in aqueous solution were investigated by potentiometric pH titration method. The stoichiometry of the most complexed species in solution was compared with corresponding crystalline complexes in the solid state. The syntheses, X-ray crystal structures, and solution studies of three new coordination compounds based upon Mn(II), Zn(II), and Ce(III) atoms together with solution studies of previously synthesized coordination compounds by our research groups containing Ni(II), Cu(II), and Cd(II) atoms have been reported here, for the first time.

Anion−π and π−π Cooperative Interactions Regulating the Self-Assembly of Nitrate−Triazine−Triazine Complexes

We theoretically investigate the cooperative enhancement of the interactions between anions and electron-deficient aromatics by pi-pi stacking, focusing on the recent crystallographic observation of anion-pi-pi interactions in a synthesized coordination compound based on 1,3,5-triazine moieties. Using a combination of state-of-the-art dispersion-corrected density functional and quantum Monte Carlo calculations, we rationalize the unusual structural features observed in this nitrate-triazine-triazine complex. We show that the triazine rings are staggered and bent and slip with respect to each other with the nitrate bound off-center in a T-like configuration. Our results indicate that this pi-pi stacking is not simply enforced by the coordination of the triazines within the particular crystal structure but is regulated by cooperative anion-pi and pi-pi interactions. In the nitrate-triazine-triazine complex, this cooperative effect amounts to 6% of the total binding energy. Ways to further increase this energetic enhancement in the design of anion-host architectures are discussed.

Synthesis, structure and physicochemical properties of zinc and copper complexes based on sulfonamides containing 8-aminoquinoline ligands

Sulfonamides obtained by reaction of 8-aminoquinoline with 4-nitrobenzenesulfonylchloride and 2,4,6-triisopropylbenzenesulfonyl chloride were used to synthesize coordination compounds with CuII and ZnII with a ML2 composition. Determination of the crystal structures of the resulting zinc and copper complexes by X-ray diffraction show a distorted tetrahedral environment for the [Cu(qnbsa)2], [Cu(qibsa)2] and [Zn(qibsa)2] complexes in which the sulfonamide group acts as a bidentate ligand through the nitrogen atoms from the sulfonamidate and quinoline groups. The complex [Zn(qnbsa)2] crystallizes with a water molecule from the solvent and the Zn is five-coordinated and shows a bipyramidal-trigonal geometry. The electrochemical and electronic spectroscopy properties of the copper complexes are also discussed.

Electrolytic reduction of 99TcO 4- with inert electrodes an alternative procedure to synthesize coordination compounds of 99Tc

Electrolytic reduction of 99TcO 4- with inert electrodes an alternative procedure to synthesize coordination compounds of 99Tc

Synthesis, structure, and antibacterial activity of coordination compounds of 3D-elements with furfural semicarbazone

It is known from [2, 3] that furfural and its derivatives serve as starting materials for the preparation of the most varied compounds with beneficial properties, among which there are also medicinal preparations with an antimicrobial activity [i]. To search for new compounds with bacteriostatic activity, in the present work we synthesized coordination compounds of Fe(2+), Co(2+), Ni(2+), Cu(2+), and Zn with furfural semicarbazone (I), established their composition, suggested the structure of the complexes obtained, and clarified the influence of these factors on the antimicrobial activity. As test microbes, we used four standard strains of Staphylococcus aureus (209P, Smith, Cowan i, Wood 46), Staphylococcus epidermidis strain 42a, Bacillus cereus strain 8035, Bacillus anthracis (anthrax capsuleless STI vaccine and capsule-forming strain 71/12 for vaccines), and Escherichia coli strain KI2.

Metallsubstituierte VB-elementsysteme : II. Phosphido-übergangsmetallkomplexe mit freier donor-funktion

Transition metal-substituted dioxaphospholanes are prepared by the reaction of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane with VIA metal-carbonyl anions. As a consequence of the pronounced basicity of the VB element this species can be readily converted to bridged dinuclear or cationic mononuclear complexes. Attempts to synthesize coordination compounds with terminal (CH 3) 2 P -groups yield diphosphinemetal cations via phosphorus—phosphorus coupling. The product is changed in the presence of strong electrophiles.