Qing‐Jin Meng

Synthesis, studies and molecular structure of trinuclear cyanide-bridged copperiron complexes

Abstract Three new trinuclear complexes: [(NO)(CN) 4 FeCNCu(en) 2 NCFe(CN) 4 (NO)][Cu(en) 2 ] ( 1 ), [(NO)(CN) 4 FeCNCu(pn) 2 NCFe(CN) 4 (NO)][Cu(pn) 2 ]·H 2 O ( 2 ), and [(NO)(CN) 4 FeCNCu(tn) 2 NCFe(CN) 4 (NO)][Cu(tn) 2 ]·2H 2 O ( 3 ) (where en=ethylenediammine, pn=1,2-diaminopropane, and tn=1,3-diaminopropane) have been synthesized. Their properties have been studied by IR spectra, UV–Vis spectra, cyclic voltammetry and magnetic balance measurement. Crystallographic data for 1 : triclinic, P 1 , a =7.1185(3), b =8.8764(3), c =13.4108(5) A, α =88.1150(10), β =87.6790(10), γ =75.9690(10)°, Z =1. Complex 1 consists of a discrete [Cu(en) 2 ] 2+ and a [(NO)(CN) 4 FeCNCu(en) 2 NCFe(CN) 4 (NO)] 2− in which the Cu(II) centre is coordinated by six nitrogen atoms and is linked by two CN groups.

Synthesis and spectroscopic studies of trinuclear uranyl complexes with compartmental ligands H4L derived from 2,6-dipicolinoyl-hydrazine and 4-acyl-1-phenyl-3-methyl-pyrazolones-5 (where acyl = benzoyl, acetyl, iso-butyryl or iso-valeroyl)

SummaryThe potentially trinucleating ligands H4L were synthesized in situ by reacting 2,6-dipicolinoyl-hydrazine with 4-acyl-1-phenyl-3-methyl-pyrazolones-5 (acyl = benzoyl, acetyl, iso-butyryl or iso-valeroyl) in a 1∶2 molar ratio. These ligands react with an excess of uranyl acetate dihydrate to yield trinucleating uranyl complexes [(UO2)3(L)(DMF)4(OAc)2] · (H2O)5. Tentative structures for the complexes have been proposed on the basis of elemental analyses, i.r. and electronic data. The force constant (f) for the vas(O=U=O) vibration and values for the U-O distance, RU-O, are calculated. The spectral studies support the trinuclear structure.

Synthesis and properties of cyano-bridged nickel(II)-iron(III) complexes

SummaryFour kinds of novel CN-bridged NiII-FeIII complexes, [NiLn(NC)Fe(CN)5] −, have been synthesized and characterized by elemental analysis, i.r. and u.v.-vis. spectral analysis, and magnetic moments. The formation of cyanide bridges is evident from the i.r. and u.v.-vis. spectra by the appearance of v(CN) shifts and changes in λmax with respect to the mononuclear parent complex [Fe(CN)6]3−. The magnetic properties indicate the existence of magnetic spin interactions between NiII and FeIII through the cyanide bridge.

Synthesis, structure, spectral and magnetic properties of a dinuclear copper(II)/nickel(II) complex bridged by glyoximate groups

Abstract A new dinuclear complex of formula [(tmen)(H2O)2Ni(Hdmg)(dmg)Cu]·ClO4 (H2dmg=dimethylglyoxime, tmen=tetramethylenediamine) has been synthesized. The crystal structure of the complex has been solved by a single-crystal X-ray diffraction method. The structure consists of one cationic dinuclear complex, [(tmen)(H2O)2Ni(Hdmg)(dmg)Cu]+, and one anion, ClO4−. In the dinuclear cationic complex the copper(II) ion and the nickel(II) ion are bridged by two oximate groups, one through the nitrogen and oxygen atoms and the other only through the oxygen atom. The intramolecular Cu⋯Ni distance is 3.424 A. The geometry around the copper atom is a distorted square pyramid, and the geometry around the nickel atom is a distorted octahedron. Variable-temperature magnetic susceptibility measurements (75–300 K) on the title complex revealed the occurrence of an intramolecular antiferromagnetic interaction through the oximate bridges. The IR and UV–Vis spectra have also been investigated.

2-Methyl-1-(4-nitro­benzyl)pyridinium bis­(maleo­nitrile­di­thiol­ato)­nickelate(III)

In the title complex, 2-methyl-1-(4-nitrobenzyl)pyridinium bis(1,2-dicyanoethene-1,2-dithiolato)nickelate(III), (C(13)H(13)N(2)O(2))[Ni(C(4)N(2)S(2))(2)], the most prominent general structural feature of the complex is the completely segregated columnar stacks of anions and cations. Within the cation column, there may be stacking interactions between adjacent nitro groups and benzene rings.

Preparation and electrochemistry of mixed nuclear complexes (OC)3 CrAreneCCo3(CO)9

SummaryFour new mixed nuclear complexes of general formula (OC)3CrAreneCCo3(CO)9, prepared by reacting (OC)3-CrAreneHgAreneCr(Co)3 with HCCo3(CO)9, were characterized by elemental analyses, i.r. and u.v. spectra. The complexes were electrochemically oxidized in acetone solution by an irreversible multi-electron process at ambient temperature, but displayed a chemically reversible one-electron process at −25°C. The resulting stable cation was easily attacked by nucleophiles such as PPh3. The results indicated that low-temperature cyclic voltammetry(LTCV) in acetone might be a useful way to study (arene)tricarbonylchromium complexes.

2,3-Bis(4-nitrobenzylthio)maleonitrile

The maleonitrile moiety of the title compound, (2Z)-2, 3-bis[(4-nitrobenzyl)sulfanyl]but-2-enedinitrile, C(18)H(12)N(4)O(4)S(2), is almost planar. The two benzene rings are nearly parallel to each other and perpendicular to the maleonitrile plane. Intermolecular S.S and pi-pi interactions are observed in the crystal structure.