Jianshen Feng

Kinetic Study of the Hydrolysis of BNPP by the Cerium(III) Complex

5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane (L) was synthesized and characterized. The kinetics of hydrolysis of bis(p-nitrophenyl)phosphate (BNPP) in the catalytic system containing macrocyclic ligand and cerium(III) was investigated. This catalytic system show high catalytic activity and better reproducibility and stability than other similar systems in the range of pH of around 5.6–7.2. The stoichiometry and spectral analysis showed that the real active species is the macrocyclic complex of cerium(III). Based on the analytical results of the specific absorption spectra, an intramolecular nucleophilic substitution mechanism for the catalytic hydrolysis of BNPP is proposed, a correlative kinetic mathematical model is established, and the corresponding thermodynamic and kinetic constants are calculated.

A 2D Cd(II)-MOF as a multifunctional luminescencent sensor for nitroaromatics, iron(III) and chromate ions

Abstract A Cd(II)-MOF, {[Cd(L)(4,4′-bipy)]·H2O·DMF}n (1) (L = nicotinic acid (2,4-dihydroxybenzylidene)-hydrazide and 4,4′-bipy = 4,4′-bipyridine), has been synthesized and characterized by microanalyses, FTIR, TGA, and single-crystal X-ray diffraction. Additionally, powder X-ray diffraction was performed to check the phase purity of the synthesized compound. Single-crystal X-ray diffraction reveals that 1 has a 2D grid network. Photoluminescent sensing of nitrobenzene, Fe(III) and CrO42− ions indicates that 1 could be a candidate for developing selective luminescent sensors for these species. Theoretical calculations have been performed to gain insight into the possible mechanism of quenching effect in emission on addition of nitrobenzene in 1 which supports the mechanism operating through ground state charge transfer between 1 and nitrobenzene.

Kinetic Study on p-Nitrophenyl Picolinate Hydrolysis Promoted by the Complex Bis(O,O′-di(2-Benzyl)Dithiophosphato)Nickel(II)

The complex Ni[S2P(OCH2Ph)2]2 (MR) was synthesised and characterised by elemental analysis, IR spectroscopy and 1H NMR spectroscopy. The hydrolysis of p-nitrophenyl picolinate (PNPP) as promoted by this complex was investigated by the UV-vis method, the results showing that MR acts as a very efficient catalyst. The specific absorption spectra of the hydrolytic reaction systems indicated that the key intermediate, made up of PNPP and MR was formed during reaction. Based on these spectra, a mechanism for the catalytic hydrolysis of PNPP has been proposed and a kinetic mathematical model established.

(5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene)nickel(II) bis­[O,O′-bis­(4-tert-butyl­phen­yl) dithio­phosphate]

The title salt, [Ni(C16H32N4)](C20H26O2PS2)2, comprises a centrosymmetric [Ni(Me6[14]dieneN4)]2+ dication (Me6[14]dieneN4 is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) and two O,O′-bis(4-tert-butylphenyl) dithiophosphate anions. The NiII ion lies on an inversion centre and displays a slightly distorted NiN4 square-planar chelation arrangement with four N atoms from the Me6[14]dieneN4 macrocycle. Two S atoms from symmetry-related anions are located in pseudo-axial positions with respect to the NiII ion, with Ni⋯S distances of 3.2991 (7) Å. Intermolecular N—H⋯S and C—H⋯S hydrogen bonds link the complex cation and pair of anions into a 1:2 type salt.

(meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetra­azacyclo­tetra­deca­ne)copper(II) bis­(O,S-dibenzyl dithio­phosphate)

In the crystal structure of the title compound, [Cu(C16H36N4)](C14H14O2PS2)2, the CuII atom is located on an inversion center and is chelated by four N atoms of the macrocyclic meso-5,5,7,12,12,14- hexamethyl-1,4,8,11-tetraazacyclotetradecane ligand in a square-planar geometry, with Cu—N distances of 2.013 (3) and 2.014 (3) Å. In the crystal structure, one O,S-dibenzyl dithiophosphate counter-anion links with the CuII complex cation through N—H⋯O and N—H⋯S hydrogen bonding. During the synthesis, the structure of the anion re-arranged from O,O′-dibenzyl dithiophosphate in the starting material to O,S-dibenzyl dithiophosphate in the title compound.

(meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)nickel(II) bis­[O,O′-bis­(4-methyl­phen­yl) thio­phosphate]

In the centrosymmetric title complex, [Ni(C16H36N4)](C14H14O3PS)2, the NiII ion is coordinated by four N atoms and two O atoms within a slightly distorted NiN4O2 octahedral geometry. The asymmetric unit consits of one NiII ion that is located on a center of inversion, half of the macrocylic ligand and one anion occupying general positions. Intramolecular N—H⋯O and N—H⋯S hydrogen bonding is found between the macrocyclic ligand and the monothiophosphate anion.

(C-meso-N-meso-5,12-Dimethyl-7,14-diphenyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene)copper(II) bis­[O,O′-bis­(4-methyl­phen­yl)dithio­phosphate]

In the title compound, [Cu(C24H32N4)](C14H14O2PS2)2, the CuII atom lies on an inversion center and is chelated by the macrocyclic ligand in a distorted CuN4 square-planar geometry. Two O,O′-bis(4-methylphenyl)dithiophosphate anions occupy the axial positions with long Cu⋯S distances of 3.0090 (8) Å. Intermolecular N—H⋯S and C—H⋯S hydrogen bonding is present between the anions and the cation.

(meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetra­aza­cyclo­tetra­deca­ne)copper(II) bis­[O,O′-(o-phenyl­ene)dithio­phosphate]

In the title compound, [Cu(C16H36N4)](C6H4O2PS2)2, the CuII cation lies on an inversion center and is chelated by the macrocyclic tetraamine ligand in a slightly distorted CuN4 square-planar geometry. The axial positions are occupied by two O,O′-(o-phenylene)dithiophosphate anions with long Cu⋯S distances of 3.0940 (7) Å. Intermolecular N—H⋯S and C—H⋯O hydrogen bonding is present between the anions and the cation and helps to stabilize the crystal structure.