Synthesis, Structural Characterization, and Hirschfeld Surface Analysis of a New Cu(II) Complex and Its Role in Photocatalytic CO2 Reduction.

A new Cu(II) complex, [CuL1L2(CH3COO)2(H2O)]·H2O, was synthesized by the reaction of Cu(CH3COO)2·H2O, 6-phenylpyridine-2-carboxylic acid (HL1), and 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine (L2) in ethanol-water (v:v = 1:1) solution. The Cu(II) complex was characterized using elemental analysis, IR, UV-vis, TG-DTA, and single-crystal X-ray analysis. The fluorescence properties of the copper complex were also evaluated. The structural analysis results show that the Cu(II) complex crystallizes in the triclinic system with space group P-1. The Cu(II) ion in the complex is five-coordinated with one O atom (O2) and one N atom (N1) from one 6-phenylpyridine-2-carboxylate ligand (L1), one N atom (N2) from 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine ligand (L2), one O atom (O4) from acetate, and one O atom (O5) from a coordinated water molecule, and it adopts a distorted trigonal bipyramidal geometry. Cu(II) complex molecules form a two-dimensional layer structure through intramolecular and intermolecular O-H…O hydrogen bonding. The two-dimensional layer structures further form a three-dimensional network structure by π-π stacking interactions of aromatic rings. The analysis of the Hirschfeld surface of the Cu(II) complex shows that the H…H contacts made the most significant contribution (46.6%) to the Hirschfeld surface, followed by O…H/H…O, N…H/H…N and C…H/H…C contacts with contributions of 14.2%, 13.8%, and 10.2%, respectively. In addition, the photocatalytic CO2 reduction using Cu(II) complex as a catalyst is investigated under UV-vis light irradiation. The findings reveal that the main product is CO, with a yield of 10.34 µmol/g and a selectivity of 89.4% after three hours.

Synthesis, Structural Characterization, Hirschfeld Surface Analysis and Photocatalytic CO2 Reduction Activity of a New Dinuclear Gd(III) Complex with 6-Phenylpyridine-2-Carboxylic Acid and 1,10-Phenanthroline Ligands.

A new dinuclear Gd(III) complex was synthesized and named [Gd2(L)4(Phen)2(H2O)2(DMF)2]·2H2O·2Cl (1). Here, L is the 6-phenylpyridine-2-carboxylate anion, Phen represents 1,10-phenanthroline, DMF is called N,N-dimethylformamide, and Cl- is the chloride anion, which is characterized by IR and single crystal X-ray diffraction analysis. The structural analysis reveals that complex (1) is a cation-anion complex, and each Gd(III) ion is eight-coordinated with four O atoms (O1, O5, O2a, O4a, or O1a, O2, O4, O5a) of four different bidentate L ligands, two O atoms (O6, or O6a) of DMF molecules, two N atoms (N1, N2, or N1a, N2a) of Phen ligands, and two O atoms (O3 or O3a) of coordinated water molecules. Complex (1) forms the three-dimensional π-π stacking network structure with cavities occupied by chloride anions and uncoordinated water molecules. The Hirschfeld surface of the complex (1) shows that the H···H contacts represented the largest contribution (48.5%) to the Hirschfeld surface, followed by C···H/H···C and O···H/H···O contacts with contributions of 27.2% and 6.0%, respectively. To understand the electronic structure of the complex (1), the DFT calculations have been performed. The photocatalytic CO2 reduction activity shows complex (1) has excellent catalytic activity with yields of 22.1 µmol/g (CO) and 6.0 µmol/g (CH4) after three hours. And the selectivity of CO can achieve 78.5%.

A Luminescent Cd-MOF Used as a Chemosensor for High-Efficiency Sensing of Fe3+, Cr(IV), Trinitrophenol, and Colchicine.

A Cd-MOF was constructed based on 3,5-bis(4-carboxyphenyl) pyridine under solvothermal conditions. Its structure and phase purity were verified by single-crystal X-ray diffraction. Thereafter, some studies on the morphology, structure, and luminescent properties of the compound were carried out. The compound exhibited a highly sensitive response to Fe3+, Cr(IV), trinitrophenol (TNP), and colchicine based on the fluorescence-quenching mechanism. The possible mechanism of luminescence quenching was discussed in detail.

Hexaaqua-magnesium bis-{4-[(5-bromo-2-hy-droxy-benzyl-idene)amino]-benzene-sulfonate} dihydrate.

In the title hydrated mol-ecular salt, [Mg(H(2)O)(6)](C(13)H(9)BrNO(4)S)(2)·2H(2)O, the Mg(2+) ion (site symmetry ) adopts a near regular MgO(6) octa-hedral coordination geometry. In the anion, the dihedral angle between the aromatic rings is 2.5 (2)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring. In the crystal, the components are linked by O-H⋯O and O-H⋯Br hydrogen bonds.

Aqua-dipyridine-bis-(N-p-tolysulfonyl-l-leucinato)nickel(II).

In each of the two mol-ecules in the asymmetric unit of the title compound, [Ni(C(13)H(18)NO(4)S)(2)(C(5)H(5)N)(2)(H(2)O)], the geometry of the Ni(2+) ion is an extremely distorted trans-NiN(2)O(4) octa-hedron, arising from its coordination by one water mol-ecule, two pyridine mol-ecules, and one O-monodentate and one O,O'-bidentate deprotonated N-p-tolysulfonyl-l-leucine ligand. In the crystal, mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds, forming chains along the c axis. An intra-molecular O-H⋯O hydrogen bond occurs in one of the mol-ecules.

(4-Amino-3-methyl-benzene-sulfonato)tri-µ-aqua-penta-aqua-disodium 4-amino-3-methyl-benzene-sulfonate.

In the title compound, [Na(2)(C(7)H(8)NO(3)S)(H(2)O)(8)](C(7)H(8)NO(3)S), one Na(+) ion is bonded to six water mol-ecules in a distorted octa-hedral arrangement while the other is bonded to five water mol-ecules and one O atom of a 4-amino-3-methyl-benzene-sulfonate anion, also yielding a distorted NaO(6) octa-hedron. Three of the water molecules bridge the metal ions and an intra-molecular O-H⋯O hydrogen bond helps to establish the conformation. In the crystal, the component species inter-act by way of O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds.

Hexaaqua-magnesium(II) bis-[4-(3-eth-oxy-2-hydroxy-benzyl-ideneamino)-3-methyl-benzene-sulfonate].

In the title compound, [Mg(H(2)O)(6)](C(16)H(16)NO(5)S)(2), the Mg(2+) ion (site symmetry 2) adopts an almost regular octa-hedral coordination geometry. The anion is stabilized by an intra-molecular O-H⋯N hydrogen bond, generating an S(6) ring, and the dihedral angle between the aromatic rings is 41.02 (7)°. In the crystal, the cations and anions are linked by O-H⋯O hydrogen bonds, generating sheets lying parallel to (100).

µ-2,2'-(Azinodimethylene)dibenzene-sulfonato-bis-[hepta-aqua-europium(III)] bis-[2,2'-(azino-dimethylene)dibenzene-sulfonate] deca-hydrate.

In the title compound, [Eu(2)(C(14)H(10)N(2)O(6)S(2))(H(2)O)(14)](C(14)H(10)N(2)O(6)S(2))(2)·10H(2)O, the complete bimetallic cation is generated by crystallographic inversion symmetry. The Eu atom adopts a distorted dodeca-hedral coordination arising from one O-bonded 2,2'-azinodibenzene-sulfonate ligand and seven water mol-ecules. In the crystal structure, the components are linked by multiple O-H⋯O and O-H⋯N hydrogen bonds.

Tetra-aqua-bis[2-(thio-semi-carbazono-methyl)benzene-sulfonato]manganese(II).

In the title compound, [Mn(C(8)H(8)N(3)O(3)S(2))(2)(H(2)O)(4)], the Mn(II) atom (site symmetry ) adopts a slightly distorted octa-hedral MnO(6) geometry. The mol-ecular conformation is supported by N-H⋯N and O-H⋯O hydrogen bonds. In the crystal, mol-ecules inter-act by O-H⋯O, O-H⋯S, N-H⋯O and N-H⋯S hydrogen bonds, thereby forming (011) sheets.

4-[(4-Diethyl-amino-2-hydroxy-benzyl-idene)ammonio]-3-methyl-benzene-sulfonate.

In the zwitterionic title compound, C(18)H(22)N(2)O(4)S, the dihedral angle between the aromatic rings is 16.39 (11)° and an intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains propagating in [01].

Penta-aqua-bis[4-(2-hydroxy-benzyl-idene-amino)benzene-sulfonato]lead(II).

In the structure of the title compound, [Pb(C(13)H(10)NO(4)S)(2)(H(2)O)(5)], two S-O bonds and one C-N bond have lengths of 1.421 (9), 1.425 (8) and 1.268 (11) Å, respectively, which suggests they are double bonds. Mol-ecules form a two-dimensional layered structure via O-H⋯O and O-H⋯N inter-actions. The Pb atom adopts distorted cubo-octahedral coordination.

Hexaaqua-zinc(II) bis-[4-(2-hydroxy-benzyl-ideneamino)benzene-sulfonate].

In the title compound, [Zn(H(2)O)(6)](C(13)H(10)NO(4)S)(2), a distorted ZnO(6) octa-hedron results from the coordination by the six water mol-ecules. Only three of the water molecules are crystallographically unique, as the Zn atom lies on an inversion center. The Zn-O bond lengths are in the range 2.054 (4)-2.073 (4) Å. A network of hydrogen bonds helps to establish the crystal packing.

N-(1-Naphth-yl)acetoacetamide.

The title compound, C(14)H(13)NO(2), exists in the keto form. An N-H⋯O hydrogen bond helps to establish the packing.

{2,2'-[4-Methyl-4-aza-heptane-1,7-diylbis(nitrilo-methyl-idyne)]diphenolato}zinc(II).

In the title compound, [Zn(C(21)H(25)N(3)O(2))], the Zn(II) atom is five-coordinate from three N donor atoms and two O donor atoms of the dianion ligand in a distorted trigonal-bipyramidal arrangement. Three methyl-ene groups of the ligand are disordered over two orientations in a 0.555 (6):0.445 (6) ratio.

Bis(2-amino-pyrimidine-κN)diaqua-dinitrato-κO;κO,O'-cadmium(II) monohydrate.

In the title compound, [Cd(NO(3))(2)(C(4)H(5)N(3))(2)(H(2)O)(2)]·H(2)O, the Cd atom is seven-coordinated by two 2-amino-pyrimidine mol-ecules, two water mol-ecules, one bidentate nitrate anion and one monodentate nitrate anion. A network of N-H⋯O, N-H⋯N and O-H⋯O hydrogen bonds helps to consolidate the crystal structure.

N'-(3-Ethoxy-2-hydroxybenzylidene)-benzenesulfonohydrazide.

There are two mol-ecules in the asymmetric unit of the title compound, C(15)H(16)N(2)O(4)S, both of which are stabilized by an intra-molecular O-H⋯N hydrogen bond. Inter-molecular N-H⋯O hydrogen bonds lead to [101] chains of mol-ecules in the crystal structure.

1-Hydroxymethyl-3,12-dioxa-14-aza-tetracyclo[9.2.1.0.0]tetradecane.

In the title fused-ring compound, C(12)H(13)NO(3), the two five-membered C(3)NO rings both approximate to envelope conformations with C atoms in the flap positions. The OH group of the pendant CH(2)OH unit is disordered over two positions in a 0.528 (5):0.472 (5) ratio. One of the OH groups participates in an O-H⋯N hydrogen bond, generating centrosymmetric dimers in the crystal structure.

Hexaaqua-cobalt(II) bis-[4-(2-hydroxy-benzyl-ideneamino)-benzene-sulfonate].

In the cation of the title compound, [Co(H(2)O)(6)](C(13)H(10)NO(4)S)(2), the Co atom lies on a centre of symmetry and its coordination geometry is octahedral. The crystal structure is stabilized by water-anion O-H⋯O hydrogen bonds. An intra-molecular O-H⋯N hydrogen bond occurs in the anion.

Bis[2-acetyl-3-methyl-pyrazine (2-hydroxy-benzo-yl)hydrazonato]zinc(II) monohydrate.

In the title compound, [Zn(C(14)H(13)N(4)O(2))(2)]·H(2)O, the Zn(II) centre is six-coordinated by four N and two O donors of two 2-acetyl-3-methyl-pyrazine (2-hydroxy-benzo-yl)hydrazonate ligands, and forms a distorted octa-hedral structure.

2-Acetyl-3-methyl-pyrazine phenyl-sulfonyl-hydrazone.

In the title compound, C(13)H(14)N(4)O(2)S, the dihedral angle between the aromatic rings is 55.42 (14)°. In the crystal structure, an N-H⋯O hydrogen bond leads to chains of mol-ecules along [001].