• CHINNAPPAN SIVASANKAR

Articles written in Journal of Chemical Sciences

• Synthesis, spectroscopic characterization and electronic structure of some new Cu(I) carbene complexes

Reaction of oligomeric Cu(I) complexes [Cu(Μ-S-C(=NR)(O-Ar-CH3)]n with Lewis acids gave Cu(I) carbene complexes, which were characterized by1H and13C NMR spectroscopy. Cu(I) carbene complexes could be directly generated from RNCS, Cu(I)-OAr and Lewis acids; this method can be used to prepare Cu(I) carbene complexes with different substitutents on the carbene carbon. The complexes were unreactive towards olefins and do not undergo cyclopropanation. Electronic structure calculations (DFT) show that the charge on the carbene carbon plays an important role in controlling the reactivity of the carbene complex.

• Functionalization of N2 to NH3 via direct N ≡ N bond cleavage using M(III)(NMe2)3 (M=W/Mo): A theoretical study

Atmospheric N2 can be cleaved directly to yield metal-nitride (before proceeding to the functionalization of N$_\alpha$ of coordinated N2) and subsequently functionalized to ammonia using M(III)(NMe2)3 (M = W/Mo) as a catalyst, and suitable proton and electron sources. The calculated energies of thermodynamic and kinetic states of the various intermediates and transition states in the reaction coordinate to yield ammonia confirmed the viability of the proposed reaction pathway. Rationale of different pathways have been examined and discussed in detail. Changes in the structural features of the catalyst and some important intermediates and transition states have also been examined.

• Possibility of reducing the coordinated dinitrogen into ammonia and hydrazine using [Ru-L] (L = triamidoamine) and FLP-H2: A DFT study

DFT studies have been executed on a hypothetical Ru-triamidoamine complex to understand the possibility of synthesizing ammonia and hydrazine from the dinitrogen at normal temperature and pressure in heptane. In this present study, we utilized the H2 in the form of FLP-H2 complex and reacted with Rutriamidoamine complex. We have added three H+ and H- parts of FLP-H2 to the Ru complex in a stepwise manner as an alternate way to yield NH3/N2H4. The catalytic cycle for the formation of NH3 and N2H4 were found to be energetically feasible. We have also observed some thermodynamically feasible six coordinate

[M]-H intermediates.

• Molecular and electronic structure analysis of [Fe(CO)4(SiX)] (X = O, S, Se and Te): a DFT study

DFT quantum calculations using B3LYP level of theory have been done for Fe(CO)5 and for the axial and equatorial isomers of [Fe(CO)4(SiX)] (X = O, S, Se, Te). The total energy analysis shows the equatorial isomer to be more stable than the axial isomer. The data obtained from the NPA and EDA analysis reveals the bonding nature of these complexes. The WBI analysis reveals the bond index of M-SiX bond. The HOMO-LUMO energy gap of the complexes obtained from the FMO analysis lies in the 3.75 to 5.52 eVrange, which is lesser than that found in Fe(CO)5. NBO analysis shows that the Fe atom’s bond contribution(in Fe-Si bond) is lesser than that of Si atom. It shows a similar contribution to the carbonyl (in Fe-C bond)group, but the contribution from C atom is higher when compared to that of the Si atom.

The molecular and electronic structural analysis is done computationally using DFT on the axial and equatorial isomers of [Fe(CO)4(SiX)] (where, X = O, S, Se, Te) as well as the parent complex Fe(CO)5. The NPA, NBO, EDA, CDA, and WBI analysis is done on the 8 different [Fe(CO)4(SiX)] complexes where the Si-X bond exists in the axial and equatorial position and they are subsequently reported.

• # Journal of Chemical Sciences

Volume 135, 2023
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Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019