NOPR Collection:

The first application of illuminated ferrofluid towards catalytic photoreduction of nitrogen by visible light

2017-05-24T07:21:54Z

Title: The first application of illuminated ferrofluid towards catalytic photoreduction of nitrogen by visible light Authors: Khan, M M Taqui; Pant, R P; Rao, N N; Chatterjee, Debabrata; Mehta, R V Abstract: The photoreduction of N₂to ammonia rate of 0.03 mole of NH₃ gm^-1 hr^-1 catalyst is described. The product formation of ammonia is 0.02. Page(s): 391-392

Synthesis and NMR spectral investigations of cycloocta-1,5-dieneiridium(I) complexes containing substituted benzimidazoles-Anomalous shielding of iso-propyl protons in [IrCl(COD)( i-PrbzlH)]

2017-05-24T07:19:04Z

Title: Synthesis and NMR spectral investigations of cycloocta-1,5-dieneiridium(I) complexes containing substituted benzimidazoles-Anomalous shielding of iso-propyl protons in [IrCl(COD)( i-PrbzlH)] Authors: Ramaswamy, Y S; Halesha, R; Gowda, N M N; Reddy, G K N Abstract: The bridge splitting reaction of the dimer [lr(µ-Cl)(COD)]₂, where COD is cycloocta-1,5-diene, with 2-substituted benzimidazoles (R-bzlH) in acetone affords mononuclear complexes of the formula [IrCI(COD)(R-bzlH)] [R=H, methyl (Me), ethyl (Et), propyl(n-Pr or i-Pr), butyl(n-Bu) or 2'-quinolyl (Qnl)].The presence of triethylamine in the system drives the reaction towards trimerisation to provide complexes of the type [Ir(COD)(µ-R-bzl)]₃(R=H, Me, Et, n-Pr or n-Bu). Treatment of the mononuclear complexes with PPh₃ in presence of NaCIO₄ produces cationic species of the type [Ir(COD)(PPh₃)(R-bzlH)]CIO_4.The ¹H and ¹³CNMR spectral features of [lrCI(COD)(i-PrbzlH)] suggest the presence of conformers in solution. The preferred orientation of the isopropyl group in one of the conformers, apparently caused by steric effect, is manifested in the anomalous shielding of the methyl protons which resonate at δ - 0.28 ppm. This seems to be the first obervation of an unusual behaviour of isopropyl substituent of the N-heterocycle in an organometallic complex. The ³¹P NMR spectra of the cationic complexes display a downfield coordination-induced shift of δ 18-22 ppm for PPh₃. The ¹H{¹H} correlated spectra suggest a trimeric structure for [lr(COD)(µ-R-bzl)]_n in chloroform. Displacement of COD by CO yields cis-dicarbonyl derivatives of the composition [Ir(CO)₂(µ-R-bzl)]_n. Page(s): 393-399

Monomeric and dimeric manganese(II) complexes of N,N,N',N'-tetrakis [(2-benzimidazolyl)-methyl]-1,2-ethanediamine and its derivatives

2017-05-24T07:00:34Z

Title: Monomeric and dimeric manganese(II) complexes of N,N,N',N'-tetrakis [(2-benzimidazolyl)-methyl]-1,2-ethanediamine and its derivatives Authors: Tripathi, Adarsh K; Sharma, K K; Mathur, Pavan Abstract: Two types of manganese(II) complexes of N, N, N', N'-tetrakis[(2-benzimidazolyl)methyl]1, 2-ethanediamine (EDTB) and its N-methyl (Me-EDTB) and N-ethyl(Et-EDTB) derivatives have been synthesized and characterized. Solution EPR of the [Mn₂(EDTB) (OAC)₄] in methanol at 142,K indicates that there are the equivalent Mn(II) ions coupled by an exchange interaction, fostered by bridging acetates. This is evidenced by a nearly isotropic 11-line hyperfine structure for ⁵⁵Mn with a coupling constant IAI =45 ± 5 G. The room temperature magnetic moment of 4.86 B.M. per Mn atom indicates a clear quenching of the magnetic moment below that of a monomeric Mn(II) ion. The [Mn(L)] (ClO₄)₂ type complexes:, show EPR spectra typical of monomeric Mn(II) complexes, in a trigonal prismatic environment; their room temperature magnetic moments of 5.99, ([Mn(EDTB)](CIO₄)₂), 5.88, ([Mn(Me-EDTB)] (ClO₄) and 5.46 ([Mn(Et-EDTB)] (CIO₄)₂) per Mn(II) atom are in the-range found for d⁵ monomeric Mn(II) complexes. Thus a bridging inner sphere anion- like acetate makes it difficult for the ligand to coordinate to a metal ion with all its six donor atoms, and hence a second metal ion is coordinated by the ligand, whilst a weakly coordinating anion- like perchlorate (ClO) makes it easy to bind only one metal ion. Page(s): 400-405

Synthesis and characterization of some new titanocene and zirconocene derivatives of functionalised less hindered phenols

2017-05-24T06:52:43Z

Title: Synthesis and characterization of some new titanocene and zirconocene derivatives of functionalised less hindered phenols Authors: Gupta, (Miss) R; Singh, A; Mehrotra, R C Abstract: Titanocene and zirconocene derivatives of the type CP₂MCl_(2-x) (OAr)_x[Ia:M=Ti, X= 1, Ar =3, 5-dimethylphenyl(Ar'); Ib: M=Ti, X = 2, Ar =3, 5-dimelhylphenyl(Ar'); IIa: M=Zr, X= 1, Ar =3,5-dimethylphenyl(Ar'); IIb: M=Zr, X=2, Ar =3, 5-dimethylphenyl(Ar'); IIIa: M=Zr, X = I, Ar 2,5-dimethylphenyl(Ar") and IIIb: M=Zr, Ar =2, 5-dimethylphenyl(Ar")] have been prepared and characterized by elemental analyses, IR, PMR and molecular weight measurements. Page(s): 406-408