Ju Chang Kim

Monomeric and polymeric copper(II) hexaaza macrocyclic complexes with btc anions (btc=1,2,4,5-benzenetetracarboxylic acid)

Abstract Two new copper(II) complexes with the composition [Cu(L)(btc−)2] (1) and [Cu(L)(btc2−)]n (2), where btc=1,2,4,5-benzenetetracarboxylic acid, L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, have been synthesized and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. The structure of 1 is made up of a macrocyclic copper(II) cation [Cu(L)]2+ and btc− anions. The copper(II) coordination geometry in 1 exhibits an axially elongated octahedron with four nitrogen atoms from the macrocycle and two carbonyl oxygen atoms from the btc− ligands. The structure of 2 shows a 1D coordination polymer, in which the copper(II) ions are bridged by the btc2− anions.

Syntheses, isolation, and structures of nickel(II) and copper(II) coordination polymers with a tetraaza macrocyclic ligand

Abstract The one-dimensional coordination polymers [Ni(L1)(oxalato)]n·nH2O (1) and [Cu(L1)(terephthalato)]n·2nH2O (2) have been synthesized and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. The complex 1 exhibits a novel one-dimensional polymeric structure with nickel(II) centers and bridging oxalato ligands. Two important features are observed in 1 when regarding the structure of the oxalato bridge: first, it has an unusual bis-monodentate coordination mode to nickel(II) ions; and second, it is not planar, the distortion arising forms a twisting about the carbon–carbon bond of the oxalato ligand. In 2, the ligand conformation is planar, and the distorted octahedral coordination about the copper(II) ion is completed by two bis-monodentate terephthalato ligands. The copper(II) ions in the complex are bridged by the terephthalato anions to form infinite linear chains, and each chain is linked by interchain hydrogen bonding interactions mediated through water molecules. The presence of water molecules is crucial to lead supramolecular arrays in both complexes.

Polymeric nickel(II) and copper(II) complexes with btc2− ions as bridging ligands (btc2−=1,2,4,5-benzenetetracarboxylic acid dianion)

Abstract Two new complexes of composition {[ Ni ( L )( btc 2− )]·2 H 2 O } n (1) {L=1,4,8,11-tetraazacyclotetradecane} and {[ Cu ( L )( btc 2− )]· H 2 O } n (2) were obtained by reacting [ Ni ( L )]·2 ClO 4 or [ Cu ( L )]·2 ClO 4 and btc, and their structures were determined by analytical, spectroscopic, and X-ray diffraction methods. The blue complex 1 and violet complex 2 consist of 1D polymeric chains with nickel(II) or copper(II) macrocycles and bridging btc2− ligands, respectively. In 1 the COO− groups on the 1,4-positions of the btc2− ligand are coordinated to the central nickel(II) atom, but in 2 the COOH groups on the 1,5-positions of the btc2− ligand are involved in interacting with the central copper(II) atom through an unusual carbonyl coordination.

SYNTHESES AND STRUCTURES OF NICKEL(II) AND COPPER(II) COMPLEXES WITH A 14-MEMBERED TETRAAZA MACROCYCLIC LIGAND

Abstract Nickel(II) and copper(II) complexes of 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.0 7.12 ]docosane ( L ) were prepared, isolated and characterized as trans -[Ni(CH 3 CN) 2 ( L )][PF 6 ] 2 ( 1 ) and trans -[Cu(CH 3 CN) 2 ( L )][PF 6 ] 2 ( 2 ) by UV–Vis, IR and X-ray crystallography. In complex 1 the coordination geometry about the nickel atom is close to octahedral with four equatorial nitrogen atoms from the macrocycle and two axial nitrogen atoms from acetonitrile. The solid-state electronic spectrum of 1 using the diffuse reflectance method shows a characteristic high-spin d 8 nickel(II) ion in a distorted octahedral environment. However, the spectrum of 1 dissolved in acetonitrile indicates that the square-planar species is predominant over the octahedral species. The copper ion environment in 2 is similar to that of nickel complex 1 , but the great tetragonal distortion in 2 is observed with much longer Cu–N (acetonitrile) distances than Ni–N (acetonitrile) distances in 1 . The electronic spectrum of square-planar [Cu( L )][PF 6 ] 2 in acetonitrile or the spectrum of 2 dissolved in acetonitrile in the visible region is basically similar to that of the Nujol mull solid-state diffuse reflectance spectrum of 2 , indicating that the square-planar [Cu( L )][PF 6 ] 2 coordinates to acetonitrile molecules to form 2 .

Syntheses and X-ray crystal structures of 14-membered tetraaza macrocyclic copper(II) complexes with polycarboxylate ligands

Abstract The fumarate-bridged 1D copper(II) coordination polymer, {[ Cu ( L1 )( O 2 CCH  CHCO 2 )]·6 H 2 O } n (1) ( L1 =3,14 -dimethyl-2,6,13,17-tetraazatricyclo[14.4.01.18.07.12]docosane) and the 1,2,4,5-benzenetetracarboxylate (btc2−) coordinated copper(II) mononuclear complex, [ Cu ( L1 )( C 6 H 2 ( COO ) 2 ( COOH ) 2 )] (2) have been synthesized and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. The complex 1 exhibits a novel 1D polymeric structure with copper(II) centers and bridging fumarate ligands. The complex 2 shows a monomeric structure with a square pyramidal coordination geometry around the copper(II) ion. In 2 the pentavalent around the copper atom is completed with four nitrogen atoms from the macrocycle and one oxygen atom from the btc ligand.

Structurally different nickel(II) hexaaza macrocyclic complexes with the same btc 2− anions ( btc 2− =1 ,2,4,5-benzenetetracarboxylic acid dianion)

Abstract Two novel complexes with the composition {[ Ni ( L )]·( btc 2− )} n (1) {L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane; btc2−=1,2,4,5-benzenetetracarboxylic acid dianion} and [ Ni ( L )]·( btc 2− )·( btc ) (2) were obtained from the reaction between [ Ni ( L ) Cl 2 ] and btc (btc=1,2,4,5-benzenetetracarboxylic acid), and their structures were determined by analytical, spectroscopic, and X-ray diffraction methods. The orange complex 1 contains a 1D hydrogen bonded polymeric chain with nickel(II) macrocycles and bridging btc2− ligands. The nickel(II) coordination geometry in 1 is best described as a square-plane with four Ni–N bonds. The weak interactions between the nickel(II) ions and the oxygen atoms of the btc2− ligand are also found. The yellow complex 2 has a monomeric structure which is composed of a nickel(II) macrocycle, a counter anion btc2−, and a free acid btc (btc=1,2,4,5-benzenetetracarboxylic acid). The nickel(II) coordination geometry in 2 is square-planar, where the tetra-valent nickel(II) ion is completed with four nitrogen atoms from the macrocycle. In addition to the presence of counter anion btc2−, the free acid btc is also found in 2, which participates in abundant hydrogen-bonding interactions.

Isolation and characterization of the first stable bicarbonato complex in a nickel(II) system: identification of unusual monodentate coordination

The stable monodentate Lindskog type bicarbonate nickel(ii) complex and its isomer have been prepared and fully characterized.

An infinite 1D hydrogen-bonded polymer built from an azido cobalt(III) tetraaza macrocyclic complex

Abstract A new complex of composition {[ Co ( L1 )( N 3 ) 2 ]· ClO 4 } n (1) (L1=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14.4.01.18.07.12]docosane) has been synthesized and structurally characterized by a combination of analytical, spectroscopic, and crystallographic methods. The cobalt(III) ion in 1 shows an octahedral geometry with four nitrogen atoms from the tetraaza macrocycle and two nitrogen atoms from the azide ligands. The [ Co ( L1 )( N 3 ) 2 ]· ClO 4 unit extends its structure to form the 1D polymer 1 through hydrogen bonding interactions among pre-organized N–H groups of the cobalt(III) macrocycle, azide ligands, and perchlorate anions.

Trans-bis(dicyanamido)nickel(II) complexes with polyaza macrocyclic ligands

Two new trans-bis(dicyanamido)nickel(II) macrocyclic complexes, [Ni(II)(L1){N(CN)2}2] · H2O (1) and [Ni(II)-(L3){N(CN)2}2] (2), where L1 is 3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane and L3 is 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane, have been synthesized and structurally characterized by spectroscopic and X-ray crystallographic methods. In (1) and (2), each central nickel(II) ion possesses a distorted octahedral geometry with four equatorial nitrogen atoms from the macrocycle and two axial nitrogen atoms from dicyanamide anions, which are terminally bonded to the central nickel atom. The solid state electronic spectra of (1) and (2) using the diffuse reflectance method show a characteristic high-spin d8 nickel(II) ion in a distorted octahedral environment.

Structures and magnetic properties of catena-(μ-MO4-O,O′)[Ni(II)(L)]·5H2O (M=Cr, Mo; L=3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane)

The new compounds catena -(μ-CrO 4 - O , O ′)[Ni(II)( L )]·5H 2 O and catena -(μ-MoO 4 - O , O ′)[Ni(II)(L)]·5H 2 O where L is 3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, have been synthesized and structurally characterized by spectroscopy, magnetic susceptibility and X-ray crystallography. The nickel ions of the one-dimensional chain complexes are bridged by the tetraoxometalate ([CrO 4 ] 2− or [MoO 4 ] 2− ) unit. The magnetic properties of the chain complexes in the temperature range 5–300 K indicate that there are weak ferromagnetic intrachain interactions among the nickel ions. The electronic as well as infrared spectral properties of the title complexes are also reported and discussed.