aswini kalita | Indian Institute of Technology Guwahati (original) (raw)

Papers by aswini kalita

Research paper thumbnail of Synthesis and supramolecular structures of iso- and heteropolymetallates assisted by organoamino phosphonium cations

Inorganica Chimica Acta, Jun 1, 2011

Polyoxometallate (POM) clusters represent an interesting choice of building blocks for the constr... more Polyoxometallate (POM) clusters represent an interesting choice of building blocks for the construction of inorganic–organic hybrid materials. The supramolecular aggregation of several iso-and heteropolymetallate anions in presence of various organoamino ...

Research paper thumbnail of Nitric oxide reactivity of a Cu(II) complex of an eneamine ligand that lead to the C=C bond breaking of the ligand to form amide compound

Department of Chemistry, Sipajhar College, Darrang-784 145, Assam, India <em>E-mail</em&... more Department of Chemistry, Sipajhar College, Darrang-784 145, Assam, India <em>E-mail</em>: aswinikalita2012@gmail.com <em>Manuscript received online 30 December 2019, revised 01 February 2020, accepted 29 April 2020</em> A copper(II) complex with bidentate ligand L [L, N-4-(phenylimino)pent-2-en-2-yl)benzenamine] was synthesized as its perchlorate salt. The single crystal structure for ligand L was determined as its chloride salt. The nitric oxide reactivity of the complex was studied in acetonitrile solvent. The formation of thermally unstable [Cu(II)-NO] intermediate on reaction of the complex with nitric oxide in acetonitrile solution was observed prior to the reduction of copper(II) centres to copper(I). The reduction was found to result with a mono nitrosation at the secondary amine site as well as C=C bond breaking of the ligand leads to the formation of an amide product. All the products were isolated and characterized spectroscopically. The X-ray singl...

Research paper thumbnail of CCDC 1993522: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1006417: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1006415: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1993826: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 951717: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 930725: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 930724: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 930722: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1007056: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Reductive nitrosylation of iron(III) complexes of tetradentate ligands

DESCRIPTION Two iron(III) complexes, 1 and 2 with L1 and L2 [ L1 = N,N'-bis(2-hydroxybenzyl)-... more DESCRIPTION Two iron(III) complexes, 1 and 2 with L1 and L2 [ L1 = N,N'-bis(2-hydroxybenzyl)-1,2-diaminobenzene; L2 = N,N'-bis(2-hydroxybenzyl)ethylenediamine], respectively, were synthesized and characterized. In methanol solution of the complexes, the Fe(III) centre was found to reduce in presence of NO gas. The formation of [FeIII-NO] intermediate prior to the reduction of Fe(III) center was evidenced by UV-visible, solution FT-IR, X-band EPR studies. The presence of excess NO gas leads to the reductive nitrosylation of the complexes leading to the formation of corresponding Fe(II)-nitrosyl complexes, 3 and 4, respectively. The Fe(II)-nitrosyls were isolated as solid and characterized spectroscopically. DFT calculations were performed to optimize the structures of all the complexes.

Research paper thumbnail of CCDC 930723: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Construction of anion binding motifs based on tryptophan

Research paper thumbnail of Nitric oxide reactivity of a manganese(II) complex leading to nitrosation of the ligand

Inorganica Chimica Acta, 2015

Manganese(II) complexes, [Mn(L)(Cl) 2 ], 1 and [Mn(L)(H 2 O) 2 ](ClO 4) 2 , 2 {L = N 1 ,N 2-bis((... more Manganese(II) complexes, [Mn(L)(Cl) 2 ], 1 and [Mn(L)(H 2 O) 2 ](ClO 4) 2 , 2 {L = N 1 ,N 2-bis((pyridine-2yl)methyl)ethane-1,2-diamine} were prepared and characterized. In acetonitrile solution, complex 1 did not react with nitric oxide gas. However, addition of nitric oxide gas to the acetonitrile solution of complex 2 resulted in unstable Mn(II)-nitrosyl intermediate. The formation of nitrosyl intermediate was evidenced by UV-Vis, solution FT-IR, 1 H NMR spectral studies. Subsequently, Mn(II) center in the complex 2 was undergone reduction to Mn(I) with a simultaneous N-nitrosation of the ligand. The N-nitrosated ligand was isolated and characterized. It should be noted that the corresponding Cu(II) complex of the same ligand in presence of nitric oxide was not found to yield Cu(II)-nitrosyl.

Research paper thumbnail of CCDC 1039493: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1039492: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1995064: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1995063: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1995076: Experimental Crystal Structure Determination

Research paper thumbnail of Synthesis and supramolecular structures of iso- and heteropolymetallates assisted by organoamino phosphonium cations

Inorganica Chimica Acta, Jun 1, 2011

Polyoxometallate (POM) clusters represent an interesting choice of building blocks for the constr... more Polyoxometallate (POM) clusters represent an interesting choice of building blocks for the construction of inorganic–organic hybrid materials. The supramolecular aggregation of several iso-and heteropolymetallate anions in presence of various organoamino ...

Research paper thumbnail of Nitric oxide reactivity of a Cu(II) complex of an eneamine ligand that lead to the C=C bond breaking of the ligand to form amide compound

Department of Chemistry, Sipajhar College, Darrang-784 145, Assam, India <em>E-mail</em&... more Department of Chemistry, Sipajhar College, Darrang-784 145, Assam, India <em>E-mail</em>: aswinikalita2012@gmail.com <em>Manuscript received online 30 December 2019, revised 01 February 2020, accepted 29 April 2020</em> A copper(II) complex with bidentate ligand L [L, N-4-(phenylimino)pent-2-en-2-yl)benzenamine] was synthesized as its perchlorate salt. The single crystal structure for ligand L was determined as its chloride salt. The nitric oxide reactivity of the complex was studied in acetonitrile solvent. The formation of thermally unstable [Cu(II)-NO] intermediate on reaction of the complex with nitric oxide in acetonitrile solution was observed prior to the reduction of copper(II) centres to copper(I). The reduction was found to result with a mono nitrosation at the secondary amine site as well as C=C bond breaking of the ligand leads to the formation of an amide product. All the products were isolated and characterized spectroscopically. The X-ray singl...

Research paper thumbnail of CCDC 1993522: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1006417: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1006415: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1993826: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 951717: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 930725: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 930724: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 930722: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1007056: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Reductive nitrosylation of iron(III) complexes of tetradentate ligands

DESCRIPTION Two iron(III) complexes, 1 and 2 with L1 and L2 [ L1 = N,N'-bis(2-hydroxybenzyl)-... more DESCRIPTION Two iron(III) complexes, 1 and 2 with L1 and L2 [ L1 = N,N'-bis(2-hydroxybenzyl)-1,2-diaminobenzene; L2 = N,N'-bis(2-hydroxybenzyl)ethylenediamine], respectively, were synthesized and characterized. In methanol solution of the complexes, the Fe(III) centre was found to reduce in presence of NO gas. The formation of [FeIII-NO] intermediate prior to the reduction of Fe(III) center was evidenced by UV-visible, solution FT-IR, X-band EPR studies. The presence of excess NO gas leads to the reductive nitrosylation of the complexes leading to the formation of corresponding Fe(II)-nitrosyl complexes, 3 and 4, respectively. The Fe(II)-nitrosyls were isolated as solid and characterized spectroscopically. DFT calculations were performed to optimize the structures of all the complexes.

Research paper thumbnail of CCDC 930723: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Construction of anion binding motifs based on tryptophan

Research paper thumbnail of Nitric oxide reactivity of a manganese(II) complex leading to nitrosation of the ligand

Inorganica Chimica Acta, 2015

Manganese(II) complexes, [Mn(L)(Cl) 2 ], 1 and [Mn(L)(H 2 O) 2 ](ClO 4) 2 , 2 {L = N 1 ,N 2-bis((... more Manganese(II) complexes, [Mn(L)(Cl) 2 ], 1 and [Mn(L)(H 2 O) 2 ](ClO 4) 2 , 2 {L = N 1 ,N 2-bis((pyridine-2yl)methyl)ethane-1,2-diamine} were prepared and characterized. In acetonitrile solution, complex 1 did not react with nitric oxide gas. However, addition of nitric oxide gas to the acetonitrile solution of complex 2 resulted in unstable Mn(II)-nitrosyl intermediate. The formation of nitrosyl intermediate was evidenced by UV-Vis, solution FT-IR, 1 H NMR spectral studies. Subsequently, Mn(II) center in the complex 2 was undergone reduction to Mn(I) with a simultaneous N-nitrosation of the ligand. The N-nitrosated ligand was isolated and characterized. It should be noted that the corresponding Cu(II) complex of the same ligand in presence of nitric oxide was not found to yield Cu(II)-nitrosyl.

Research paper thumbnail of CCDC 1039493: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1039492: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 1995064: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1995063: Experimental Crystal Structure Determination

Research paper thumbnail of CCDC 1995076: Experimental Crystal Structure Determination