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A novel co-crystal of 2-aminobenzimidazole and 2-[(benzoylcarbamothioyl)amino] propanoic acid is synthesized and characterized by spectroscopy, elemental analysis, GC-MS, and single crystal XRD. A computation of the structures involved in the formation of the co-crystal are carried out and their contribution to reactivity is explained. [ABSTRACT FROM AUTHOR]

The reactions of trans-[ReOX 3(PPh 3) 2] (X = Cl, Br) with 4-aminoantipyrine (H 2pap) were studied, and the complexes cis-[ReX 2(pap)(H 2pap)(PPh 3)](ReO 4) (X = Cl ( 1), Br ( 2)) were isolated. The crystal structure of 2 was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2 1 with a = 11.5145(6) Å, b = 11.5330(5) Å, c = 17.5492(9) Å, β = 105.322(2)°, V = 2247.6(2) Å 3, Z = 2, C 40H 39N 6O 6PBr 2Re 2, Mr = 1262.97, Dc = 1.866 g cm −3, F(000) = 1208 and μ(Mo Kα) = 7.244 mm −1, the final R = 0.0545 and wR = 0.1314. The ligand pap is coordinated through the doubly deprotonated amino nitrogen as an imide, and H 2pap acts as a neutral bidentate chelate, with coordination through the neutral amino nitrogen and the ketonic oxygen. Graphical Abstract: The synthesis and crystal structure of the complex cis-[ReBr 2(pap)(H 2pap)(PPh 3)](ReO 4), prepared from the reaction of trans-[ReOBr 3(PPh 3) 2] with 4-aminoantipyrine (H 2pap), is described. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

An unusual mixed crystal of a square-pyramidal oxorhenium(V), [ReOCl(Hdua)], and an octahedral imidorhenium(V) complex, [Re(dua)Cl2(PPh3)], was prepared from the reaction of trans-[ReOCl3(PPh3)2] and (6Z)-6-(2-aminobenzylideneamino)- 5-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (H3dua) in ethanol. Characterization was performed by single crystal X-ray structure determination and IR spectroscopy. The chelate Hdua is coordinated as a tridentate diamido-imine, and dua is chelated as an imido-imino-amide. [ABSTRACT FROM AUTHOR]

The neutral, mononuclear complex [ReO(mta) 2 Cl] (1) [Hmta  =  2-(methylmercapto)aniline] was prepared by reaction of trans -[ReOCl 3 (PPh 3 ) 2 ] with a twofold molar excess of Hmta in methanol. The oxo-bridged dimer (μ-O)[ReO(mta) 2 ] 2 (2) was synthesized by reacting [ReOCl 3 (PPh 3 ) 2 ] with a twofold excess of Hmta in a 9  :  1 acetone/water mixture. The compounds were characterized by spectroscopy and complex 1 also by X-ray crystallography. Complex 1 has a distorted octahedral geometry with the chloride coordinated trans to the oxo group, and with the chelating ligands in the equatorial plane in a cis-N cis-S configuration. [ABSTRACT FROM AUTHOR]

The reactivity of oxorhenium(V) precursors with the potentially N , N -donor ligand 2,2′-dipyridylamine (dpa) has been investigated. Reaction of a two-fold molar excess of dpa with trans -[ReO(OEt)Cl 2 (PPh 3 ) 2 ] in ethanol led to the isolation of [ReOCl 2 (OEt)(dpa)] ( 1 ). Spectroscopic measurements indicate that dpa is coordinated as a bidentate in the equatorial plane cis to the oxo group, with the ethoxide in the trans position. Treatment of trans -[ReOCl 3 (PPh 3 ) 2 ] with a tenfold molar excess of dpa in ethanol at reflux yielded the trans -dioxo complex [ReO 2 (dpa) 2 ]Cl ( 2 ), but with a twofold molar excess (μ-O)[{ReOCl 2 (dpa)} 2 ] ( 3a ) was isolated. The latter reaction with ( n -Bu 4 N)[ReOCl 4 ] as starting material in ethanol at room temperature led to a dark green product, also with the formulation (μ-O)[{ReOCl 2 (dpa)} 2 ] ( 3b ). These compounds were characterised by common spectroscopic techniques, and the crystal structures of 2 ·3H 2 O, 3a and 3b ·2DMSO were determined. The structure of 3b presents a nearly linear O=Re-O-Re=O group, with the two [ReOCl 2 (dpa)] halves of the dimer rotated by 180.0° about the Re-O-Re fragment away from an eclipsed conformation. In 3a , the two halves are only rotated by 61.4°. [ABSTRACT FROM AUTHOR]

The rhenium(V) complexes [ReCl 3 ( t -BuNC)(L)(PPh 3 )] ( 1 – 3 ) were isolated by the reaction of trans -[Re III Cl 3 ( t -BuNC)(PPh 3 ) 2 ] ( t -BuNC = tert -butyl isocyanide) with the ligands H 2 L (H 2 L = aniline ( 1 ), o -phenylenediamine ( 2 ), anthranilic acid ( 3 )). In all these complexes the dianionic ligands L are coordinated monodentately as the imide. However, unexpectedly, with 2-aminophenol the complexes [Re V Cl 2 ( t -BuNC)(L)(PPh 3 ) 2 ](ReO 4 ) ( 4 ) and the novel [Re III Cl 2 ( t -BuNC)(ibq)(PPh 3 ) 2 ] ( 5 ) (ibq − = 2-iminobenzoquinonate, the two-electron oxidized form of HL − ) were identified as the products. These complexes were characterized by single crystal X-ray crystallography, 1 H NMR spectrometry, IR and electronic spectroscopy, and cyclic voltammetry. To complement the experimental data, density functional theory (DFT) and time-dependent DFT methods were used to have a deeper understanding into the molecular parameters and infrared and electronic spectra of these complexes. [ABSTRACT FROM AUTHOR]

The reaction of trans -[ReOI 2 (OEt)(PPh 3 ) 2 ] with dithizone in ethanol led to the isolation of the complex salt [ReO(dz) 2 ][ReO(HL) 2 ] ( 1 ), which contains the ionic oxorhenium(V) complexes [ReO(dz) 2 ] - and [ReO(HL) 2 ] + . The new NS-donor ligand triphenylphosphazeno- N -phenylmethanethiohydrazide HL was formed by the replacement of the Ph-N group on the azoic side of dithizone by the substituted triphenylphosphine of the starting material, and is a rare example of the in situ formation of this type of ligand. The salt ( n -Bu 4 N)[ReO(dz) 2 ] ( 2 ) was isolated from the reaction of ( n -Bu 4 N)[ReOCl 4 ] with H 2 dz in ethanol. Compounds 1 and 2 were characterized by elemental analysis, FTIR, proton NMR and single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

Abstract: The reactions of [Re(CO)5Br] with the potentially bidentate ligands N,N-dialkylbenzoylthiourea (HL1) and its N,N-diphenyl derivative (HL2) were studied. In the complex fac-[Re(CO)3(HL1)2Br] (1) the two neutral HL1 ligands are coordinated in a monodentate manner via the thiourea sulfur atom. Coordination of the monoanionic chelate L2 occurs through the neutral benzoyl oxygen atom and the anionic sulfur atom, which also acts as a bridge to the second metal centre, in the dimeric complex [Re2(CO)6(L2)2] (2). The crystal structures of 1 and 2 were determined by X-ray single crystal diffraction. UV–vis absorption spectra of the complexes show the intraligand and MLCT transitions. [Copyright &y& Elsevier]

The reaction of [ReCl 3 (MeCN)(PPh 3 ) 2 ] with 2-mercapto-orotic acid (H 2 moa) in ethanol led to the isolation of the multiply-bridged dimer ( μ -Cl)( μ -O)( μ -moa) 2 [Re III Re IV (PPh 3 )] 2 ( 1 ). The compound has a Re Re bond distance of 2.5425(7) Å with a formal bond order of 2.5. The dianionic bridging ligands moa 2 − coordinate bidentately via a neutral pyrimidine nitrogen and carboxylate oxygen to one Re ion, and monodentately through a thiolate sulfur to the second metal ion. Complex 1 was characterized by FTIR, electronic spectroscopy, cyclic voltammetry, microanalysis and single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The rhenium(I) compound fac-[Re(CO)3(daa)].Hpab.H2O (Hpab = N,N'-(1,2-phenylene)bis(2′-aminobenzamide); Hdaa = 2- amino-N-(2-aminophenyl)benzamide) was synthesized from the reaction of [Re(CO)5Br] with two equivalent of Hpab in toluene. The monoanionic tridentate ligand daa was formed by the rhenium-mediated cleavage of an amido N-C bond of the potentially tetradentate ligand Hpab. The compound was characterized by IR spectroscopy and X-ray crystallography, and daa is coordinated as a diaminoamide via three nitrogen-donor atoms. [ABSTRACT FROM AUTHOR]

The reaction of trans -[ReOBr 3 (PPh 3 ) 2 ] with 5-amino-orotic acid (H 2 aoa) in ethanol led to the isolation of the triply-bridged dimer [Re IV 2 (μ-O)(μ-Br)(μ-aoa)Br(OEt) 2 (PPh 3 ) 2 ] ( 1 ). The compound has a Re Re bond distance of 2.5526(4) Å. The dianionic bridging ligand aoa coordinates bidentately via an amido nitrogen and carboxylate oxygen to one Re ion, and monodentately through a neutral carbonylic oxygen to the second metal ion. Density functional theory (DFT) calculation shows that the presence of the rhenium atoms leads to a noncollinear spin phase arrangement for the bridging atoms. [ABSTRACT FROM AUTHOR]

Abstract: The products of the reactions of [Re(CO)5Cl] with 1-(benzothiazol-2-ylidene)-3-methylthiourea (Hmbt) and bis{1,2-(benzothiazol-2-ylidene)}thiourea (Hdbt) were studied. The X-ray crystal structure of (μ-mbt)2[Re(CO)3]2 shows that bridging between the two metal centres occurs via the two thiolic sulfur atoms of the two mbt ligands. One mbt ligand is also coordinated via a benzothiazole nitrogen atom to a rhenium(I) atom, with the second mbt ligand attached to the metal via a thiourea imino nitrogen. In the complex (μ-dbt)2[Re(CO)3]2, each dbt ligand bridges two metal centres in a ‘2+1’ manner, with each rhenium atom in a N2SC3 donor atom set. [Copyright &y& Elsevier]