Chee-Hun Kwak

Synthesis and characterization of a polymeric copper (II) complex bridged with perchlorate ion: X-ray crystal structure of Cu(N,N′-bis(3-aminopropyl)ethylenediamine)(ClO4)2·H2O

Abstract The title complex was prepared by the reaction of N,N′-bis(3-aminopropyl)ethylenediamine (3,2,3-tet) and NaClO4 in the presence of copper(II) ion. The complex forms a coordination polymer bridged with μ-bidentate perchlorato ligand. The geometry around copper(II) ion is tetragonally distorted octahedron by the coordination of four nitrogens of 3,2,3-tet with square-planar arrangement and two perchlorato ligands in apical sites. An water molecule of the unit complex is located between [Cu(3,2,3-tet)] 2+ and uncoordinated perchlorate with hydrogen bonds.

Structure, magnetic and ion-exchange properties of self-assembled triaza-copper(II)-oxalate hybrides having nanoscale one-dimensional channel.

The X-ray structure, porous and magnetic property of a self-assembled network 1 is described in detail. The single crystal X-ray analysis provides 1 as a three-dimensional network, which contains two-dimensional permanent ring forming nanoscale one-dimensional channels. The inter-replacement of perchlorate and hexafluorophosphate anions in solid 1 proves its porous structure. There is somewhat strong antiferromagnetic interaction (J = -74.1 cm(-1)) between two copper(II) ions through oxalate bridge and weak antiferromagnetic interaction (J = -5.1 cm(-1) through AEP ligand.

Structure and properties of a Ni(II) macrocyclic complex containing 4-methylenepyridine as a pendant arm and photo-induced electron-transfer of its self-assembled adduct with Ru(II)–bipyridine complex

Abstract Ni(II) macrocyclic complex containing pyridine as a pendant arm ([Ni(A)]2+) was prepared and its X-ray crystal structure was determined. Pyridine ring of the complex is located above the coordination plane and water molecule links Ni(II) ion and nitrogen atom of pyridine ring in second complex, resulting to one-dimensional chain. The considerable photo-induced electron-transfer reaction was detected in the Ru(II)–Ni(II)2 self-assembled adduct of {Ru(bpy)2[Ni(A)]2}(ClO4)6 (B).

2-(2-Methyl-6-phenyl-1-propyl-1,4-dihydro­pyridin-4-yl­idene)propane­dinitrile

In the title compound, C18H17N3, the dihedral angle between the dihydropyridine and phenyl rings is 72.57 (5)° and that between the dihydropyridine ring and malononitrile plane is 5.19 (20)°. The C—C bond lengths in the pyridine ring are considerably shorter than those of normal single bonds, indicating that electrons on the dihydropyridine ring, including the non-bonding electrons of the N atom, are delocalized on the ring.

Preparation, characterization and X-ray structure of {[(3,2,3-tet)Ni(μ-CO3)Ni(3,2,3-tet)][(3,2,3-tet)Cu]}(ClO4)4: a heteronuclear trimetallic complex containing hydrogen bonds

A heteronuclear trimetallic complex {[(3,2,3-tet)Ni( μ -CO 3 )Ni(3,2,3-tet)][(3,2,3-tet)Cu]} 4+ (3,2,3-tet= N,N ′ - bis(3-aminopropyl)ethylenediamine) has been prepared by the reaction of Ni(II), 3,2,3-tet, Na 2 CO 3 and Cu(3,2,3-tet)(ClO 4 ) 2 in situ. The complex is composed of two units, [(3,2,3-tet)Ni( μ -CO 3 )Ni(3,2,3-tet)] 2+ and [Cu(3,2,3-tet)] 2+ , which are linked by hydrogen bonding. The carbonate ion in the former unit acts as a bis- μ -bidentate ligand and adopts cis arrangement, and the resulting dinuclear complex has cis - β configuration for both Ni(II) ions.

(E)-2-Amino-4-(3,3-dimethyl-2-oxobutyl-idene)-1-[2-(2-hy-droxy-eth-oxy)eth-yl]-6-methyl-1,4-dihydro-pyridine-3-carbo-nitrile.

In the title compound, C17H25N3O3, there are intramolecular hydrogen bonds between an amine H atom and the epoxy O atom, and between a dihydropyridine ring H atom and the ketone O atom. In the crystal, molecules are linked into a zigzag chain running parallel to the c axis by hydrogen bonds between the hydroxy group and the ketone O atom. There are also weak C—H⋯O and C—H⋯π interactions which link the molecules into sheets lying in the bc plane.

4,6-Di-tert-butyl-2,8-dimeth-oxy-dibenzo[b,d]furan.

In the title compound, C22H28O3, the dihedral angle between the benzene rings is 3.47 (13)° and the five-membered furan ring is essentially planar with a largest deviation of 0.0052 (14) Å. The Csp 2—Csp 2 bond length between the two benzene rings [1.443 (3) Å] is considerably shorter than those between the benzene and tertiary C atoms [1.538 (3) and 1.530 (3) Å], which are sp 2–sp 3 hybridized. C—H⋯π interactions involving the furan and benzene rings are found in the crystal structure.

(E)-7-(4-Chloro­phen­yl)-5,7-dihydro-4H-pyrano[3,4-c]isoxazole-3-carbaldehyde oxime

In the title compound, C13H11ClN2O3, the nine-membered bicycle includes an oxime group having the C=N group in an E configuration. The isoxazole ring is almost planar [r.m.s. deviation = 0.0056 Å]; the dihedral angle between the isoxazole and 4-chlorophenyl ring is 75.60 (5)°. In the crystal, intermolecular O—H⋯Nisoxazole hydrogen bonds give rise to chains running along the b axis.

Oxidative dehydrogenation of a saturated tetraaza macrocyclic nickel(II) complex: selective formation of nickel(II) complexes containing one or two imino groups

The reaction of the saturated polyaza macrocyclic nickel(II) complex [NiL1][ClO4]2(L1= C-meso-3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07.12] docosane) with concentrated HNO3 in water–methanol (1 : 1) solution yielded the low-spin nickel(III) complex [NiL1(NO3)2]ClO4. The latter is further oxidized in the presence of the acid to produce the diimine complex [NiL2]2+(L2= 3,14-dimethyl-2,6,13,17-tetraazatricyclo-[16.4.0.07.12]docosa-2,13-diene). The monoimine complex [NiL3][ClO4]2(L3= C-meso-3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.07.12] docos-5-ene) can also be prepared by the oxidative dehydrogenation reaction of [NiL1]2+ with HNO3 in water–acetonitrile (1 : 1) solution. The square-planar nickel(II) complexes of L2 and L3 were characterized. The crystal structure of [NiL3][ClO4]2 shows that the complex has a somewhat distorted square-planar geometry.