Ru-Ji Wang

Synthesis and characterization of cobalt(III) azido complexes of some pyridine ligands and X-ray crystal structure of mer-[Co(pyridine)3(N3)3] and mer-[Co(4-Picoline)3(N3)3]

Abstract A series of green cobalt(III) azido complexes of the type CoL3(N3)3, where L is pyridine, 4-amino-, 4-ethyl- or 3-methyl-pyridine, in addition to another series of brown complexes of the same type for L  4-methyl-, 4-bromo-, 4-aldehyde-, 4-acetyl, 4-cyanopyridines and methyl-, ethyl-nicotinate and isonicotinates, have been prepared by aerial or persulphate oxidation of cobalt(II). The complexes gave non-conducting solutions and their electronic spectra are discussed. The IR spectral results suggest asymmetric azido ligands, whereas the number of CoN(N3) and CoN(L) stretching bands observed in the far-IR region are consistent with mer-formulation of complexes of both series. X-ray crystal structure determinations were done for mer- [Co(py)3(N3)3] (1) and mer- [Co(4-pic)3(N3)3] (2). The coordination around the cobalt(III) ion in the discrete molecules of both compounds is approximately octahedral with mean CoN(L) distances of 1.977(7) and 1.973(12) A and CoN(N3) lengths of 1.951(9) and 1.949(10) A for 1 and 2, respectively.

REACTIONS OF CuX (X = SCN AND CN) WITH 2-BENZOYLPYRIDINE. SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF [9-OXO-INDOLO[1,2-a] PYRIDINIUM] DITHIOCYANATOCUPRATE(I) AND POLYMERIC μ-CYANO(2-BENZOYLPYRIDINE) COPPER(I)

Abstract When a mixture of excess CuSCN and 2-benzoylpyridine (2-Bzpy) stands in an ethanolic medium for about ten days in contact with air, the intramolecular oxidative cyclization of 2-Bzpy occurs with formation of the ionic compound [9-oxo-indolo[1,2-a]pyridinium]+ [Cu(SCN)2]− (1). In contrast, interaction of CuCN and 2-Bzpy in ethanol leads to formation of the polymer [Cu(CN)(2-Bzpy)]n (2). The reaction of Cu(II) and 2-Bzpy in presence of excess SCN− in ethanol affords (1) and the green monomer [Cu(SCN)2(2-Bzpy)2] (4). These complexes, along with the 1:1 CuSCN complex of 2-Bzpy (3) are studied by IR, Raman and electronic spectroscopic methods and X-ray structural analysis of (1) and (2). Crystals of (1) are monoclinic, space group P21/n (No. 14), with a = 5.887(1), b = 36.142(7), c = 7.083(1) A, B = 109.56(1)°, Z = 4, and RF = 0.033 for 2487 observed MoKα data, (2) monoclinic, space group P21/c (No. 14), a = 14.393(3), b = 8.881(2), c = 9.287(2) A, B = 103.80(3)°, Z = 4, and RF = 0.036 for 2030 observ...

Di-n-butyltin(IV) di-o-bromobenzoate, a weakly-bridged dimer

Abstract The six-coordinated tin in di-n-butylin di- o -bromobenzoate has a skew-trapezoidal bipyramidal geometry with a C-Sn-C angle of 140.5(3)°. The molecules are packed in the unit cell as weakly-bridged dimers (Sn···O 3.451(5) A).

Intermolecular C–H activation to a novel Rh nitrile bridged porphyrin coordination polymer

Abstract A novel porphryin coordination polymer, (3′-cyanophenyl)[2,3,7,8,12,13,17,18–5,10,15,20-tetramesitylporphyrinato] rhodium(III) 3, has been synthesized from the intermolecular C–H activation of the reaction of RhCl3 with porphyrin H2(tmp)(Ph)8, 1, in refluxing PhCN and the X-ray structure shows a ziz–zag chain.

Preparation and crystal structure of the complexes thallium(I) oxalohydroxamate(1–) and malono-hydroxamate(1–)

Thallium(I) oxalohydroxamate 1, Tl(HONHCOCONHO), and malonohydroxamate 2, Tl(HONHCOCH2CONHO), have been characterized as acid salts of type A2 and B2, respectively, using single-crystal X-ray diffraction. In 1 the co-ordination polyhedron around the TlI can be described as a distorted dodecahedron; the eight Tl–O bonds are divided into sets of six short and two long, the latter lying at one side of the TlI the lone-pair electrons of which are stereoactive. In 2 the co-ordination environment of TlI is square pyramidal with the lone-pair electrons oriented in the axial direction.

Structural studies of some derivatives of cis, cis-cyclohexane-1,3,5-tricarboxylic acid

Abstractcis,cis-Cyclohexane-1,3,5-tricarboxylic acid (1) its trimethyl ester (2) and their 1,3,5-trimethylated and 1,3,5-tribenzylated derivatives were prepared, and their structures studied by two-dimensional NMR spectroscopy in conjunction with X-ray crystallography. The results show that these molecules adopt a chair conformation in solution, with all the carboxyl groups in1 and all the methoxycarbonyl groups in2 occupying the equatorial positions, but with the corresponding functionalities in the alkylated derivatives occupying the axial positions. For2, its 1,3,5-tribenzylated derivative4, andcis,cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylic acid (5), the same conformational preferences are seen to persist in the crystalline state as in solution.

Preparation and reactivity of PhP(C5Me4H)2 and Ph2P(C5Me4H). X-ray crystal structures of Mo(CO)5[Ph2P(C5Me4H)] and (η5-C5Me4H)Mo(CO)(μ-PPh2)2Mo[(η5-C5Me4)P(O)Ph2](CO) · 1/4C6H14

Abstract The phosphine ligands PhP(C5Me4H)2, I, and Ph2P(C5Me4H), II, can be prepared via the interaction of PhPCl2 and Ph2PCl with two and one equivalent(s) of (C5Me4H)Li, respectively. At ambient temperature, C7H8MO(CO)4 reacts with I–II to give the corresponding Mo(CO)5L complex, III–IV [III, L = PhP(C5Me4H)2; IV, L = Ph2P(C5Me4H)], in moderate yield (60–65%). In refluxing hexane, C7H8Mo(CO)4 reacts with II to give (η5-C5Me4H)Mo(CO)(μ-PPh2)2 Mo[(η5-C5Me4)P(O)Ph2](CO)· 1/4C6H14, V, in low yield (10%). Structures of IV and V have been determined by X-ray crystallography.

Synthesis of novel dinickel(II) and nickel(II)–copper(II) bimetallic complexes derived from an acyclic dinucleating Schiff base–pyridine ligand

Novel phenolic bridged dinickel(II) and nickel(II)–copper(II) complexes are synthesized by stepwise metallation of a dinucleating compartmental Schiff base–pyridine ligand.

Novel five-co-ordinate osmium-oxo complex stabilized by diaminato ligands. Synthesis, reactivities, and x-ray crystal structure of [OsO{NHC(Me) 2C(Me)2NH}{NH2C(Me)2C(Me) 2NH}]ClO4

The six-co-ordinate trans-[Os(L)2(O)2]2+[L = NH2C(Me)2C(Me)2NH2] and five-co-ordinate [OsO{NHC(Me)2C(Me)2NH}{NH2C(Me)2C(Me)2NH}]+ complexes are in equilibrium in solution; the X-ray structure of the five-co-ordinate square pyramidal OsVI-oxo complex has been determined with a measured OsO distance of 1.72(2)A.

Synthesis, electrochemistry and X-ray crystal structure of cis-[RuIIIL1(Cl)(H2O)][ClO4]2·2H2O [L1=N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)ethylenediamine]; electrochemical oxidation of alcohols and tetrahydrofuran by cis-[RuVL1(Cl)O]2+

Reaction of K2[RuCl5(H2O)] with N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)ethylenediamine (L1) in ethanol gave cis-[RuIIIL1Cl2]+ and then cis-[RuIIIL1(Cl)(H2O)]2+ upon reaction with AgI in water. The structure of cis-[RuIIIL1(Cl)(H2O)][ClO4]2·2H2O has been established by X-ray crystallography: space group Pbca, a= 10.863(1), b= 21.548(2), c= 21.912(2)A. The measured Ru-Cl and Ru-OH2 distances are 2.307(4)A and 2.070(9)A respectively. A cyclic voltammogram of cis-[RuIIIL1(Cl)-(H2O)]2+ in 0.1 mol dm–3 CF3CO2H shows three reversible/quasi-reversible couples at 1.29, 0.93 and 0.23 V vs. saturated calomel electrode assigned to the couples RuV-RuIV, RuIV-RuIII and RuIII-RuII. The complex cis-[RuIIIL1(Cl)(H2O)]2+ is an active catalyst for the electrochemical oxidation of alcohols and tetrahydrofuran. The second-order rate constant for the oxidation of benzyl alcohol by electrochemically generated cis-[RuVL1(Cl)O]2+ is estimated to be 8.4 × 104 dm3 mol–1 s–1.