Novel Coordination Polymer of Cadmium (II) with L-Tryptophan

A new cadmium (II) polymeric coordination compound with tryptophan (Trp) of general formula {[Cd(L-Trp)2(H2O)Cl]∙(Trp)∙(H2O)}n was synthesized. The monocrystals of the investigated complex were obtained using the method of slow evaporation. The crystal and molecular structure was determined. The compound was crystallized in the orthorhombic P212121 space group. The cadmium atom was seven coordinates by two oxygen atoms from one bidentate-chelating carboxylate group of bridging Trp, two oxygen atoms from one bidentate-chelating carboxylate group from a monodentate organic ligand, one oxygen atom of water molecule, one nitrogen atom of the amino group from bridging Trp and one chlorine atom, which means that every tridentate Trp substituent was bridging towards one cadmium atom and bidentate chelating towards one another. The monodentate Trp is a zwitterionic molecule. The coordination led to the formation of 1D supramolecular chains entrapping water and Trp molecules.

Potential Application Zn-MOF/MnO2 Composite as Methanol Gas Sensor

Methanol is a simple alcohol compound which is known very volatile and to be toxic inside of human’s body. Therefore, it is necessary to develop a sensor that is capable to detect the methanol vapor in indoor air. Zn-based MOF is a polymeric coordination compound made up of ZnxOyCz inorganic cluster as the secondary building unit (SBU) and benzene dicarboxylate as the bridging ligand and formed bulky and porous material. In this research, composites of manganese oxide (MnO2) and Zn-based MOF are synthesized and characterized as material sensor for its capability towards sensing of methanol gas. Diffractogram of PXRD reveals that the synthesized Zn-MOF is crystalline and become more amorphous due to MnO2 addition. The composite was made into pellets and measured of its resistivity. The addition of MnO2 to the Zn-MOF lowered the resistivity of the Zn-MOF and the composite was found to be sensitive towards methanol vapor.

Two 1-D Coordination Polymers Containing Zinc(II) Hexaborates: [Zn(en){B6O7(OH)6}]·2H2O (en = 1,2-diaminoethane) and [Zn(pn){B6O7(OH)6}]·1.5H2O (pn = 1,2-diaminopropane)

The synthesis and characterization by single-crystal X-ray diffraction (XRD) studies of two new zinc(II) hexaborate(2−) complexes, [Zn(en){B6O7(OH)6}]·2H2O (en = 1,2-diaminoethane) (1) and [Zn(pn){B6O7(OH)6}]·1.5H2O (pn = 1,2-diaminopropane) (2), are reported. These complexes crystallize from aqueous solutions containing 10:1 ratios of B(OH)3 and the appropriate Zn(II) amine complexes ([Zn(en)3][OH]2 or [Zn(pn)3][OH]2) through self-assembly processes. The hexaborate(2−) anions in 1 and 2 are coordinated to two Zn(II) centers and form one-dimensional (1-D) polymeric coordination chains. R22(8) and R22(6) inter-chain H-bond interactions play an important role in these self-assembly processes and are discussed.

Structural diversity and photo-physical and magnetic properties of dimeric to 1D polymeric coordination polymers of lighter lanthanide(iii) dinitrobenzoates

The one-dimensional assembly of luminescent Nd(iii) mononuclear single-molecule magnets is reported.

Crystal structure ofcatena-poly[[aquabis(4-cyanobenzoato-κO)copper(II)]-μ-N,N-diethylnicotinamide-κ2N1:O]

The asymmetric unit of the title polymeric compound, [Cu(C8H4NO2)2(C10H14N2O)(H2O)]n, contains one CuIIatom, one coordinating water molecule, two 4-cyanobenzoate (CB) ligands and one coordinatingN,N-diethylnicotinamide (DENA) molecule. The DENA ligand acts as a bis-monodentate ligand, while the CB anions are monodentate. Two O atoms of the CB ligands, one O atom of the water molecule and the pyridine N atom of the DENA ligand form a slightly distorted square-planar arrangement around the CuIIatom which is completed to a square-pyramidal coordination by the apically placed O atom of the DENA ligand, with a Cu—O distance of 2.4303 (15) Å. In the two CB anions, the carboxylate groups are twisted relative to the attached benzene rings by 2.19 (12) and 3.87 (15)°, while the benzene rings are oriented at a dihedral angle of 5.52 (8)°. The DENA ligands bridge adjacent Cu2+ions, forming polymeric coordination chains running along thebaxis. In the crystal, strong water–carboxylate O—H...O hydrogen bonds link adjacent chains into layers parallel to (10-1) and weak C—H...O hydrogen bonds further stabilize the crystal structure. The cyano group C and N atoms of one of the CB ligands are disordered over two sets of sites with equal occupancies.

Synthesis, structural characterization and thermal properties of a new copper(II) one-dimensional coordination polymer based on bridgingN,N′-bis(2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine and dicyanamide ligands

The design and synthesis of polymeric coordination compounds of 3dtransition metals are of great interest in the search for functional materials. The coordination chemistry of the copper(II) ion is of interest currently due to potential applications in the areas of molecular biology and magnetochemistry. A novel coordination polymer of CuIIwith bridgingN,N′-bis(2-hydroxyphenyl)-2,2-dimethylpropane-1,3-diamine (H2L-DM) and dicyanamide (dca) ligands,catena-poly[[[μ2-2,2-dimethyl-N,N′-bis(2-oxidobenzylidene)propane-1,3-diamine-1:2κ6O,N,N′,O′:O,O′]dicopper(II)]-di-μ-dicyanamido-1:2′κ2N1:N5;2:1′κ2N1:N5], [Cu2(C19H20N2O2)(C2N3)2]n, has been synthesized and characterized by CHN elemental analysis, IR spectroscopy, thermal analysis and X-ray single-crystal diffraction analysis. Structural studies show that the CuIIcentres in the dimeric asymmetric unit adopt distorted square-pyramidal geometries, as confirmed by the Addison parameter (τ) values. The chelating characteristics of theL-DM2−ligand results in the formation of a CuIIdimer with a double phenolate bridge in the asymmetric unit. In the crystal, the dimeric units are further linked to adjacent dimeric units through μ1,5-dca bridges to produce one-dimensional polymeric chains.

The synthesis of the heterocubane cluster [{CpMn}4(μ3-P)4] as a tetrahedral shaped starting material for the formation of polymeric coordination compounds

Thermolysis of [CpMn(η6-cht)] with P4 in 1,3-diisopropylbenzene leads to the formation of the heterocubane [Cp4Mn4P4] (1) in high yields, as a rare example of ‘naked’ phosphorus containing complexes of manganese.

Unexpected fragmentations of triphosphaferrocene – formation of supramolecular assemblies containing the (1,2,4-P3C2Mes2)− ligand

An unusual fragmentation of a triphosphaferrocene is observed, when it is reacted with Cu(i) halides. As a result, a large variety of different monomeric, dimeric and 1D and 2D polymeric coordination compounds are formed.