Chinnappan Sivasankar

Colorimetric sensing of fluoride ion by new expanded calix[4]pyrrole through anion-π interaction.

Three new expanded calix[4]pyrroles were synthesized, where the two dialkylldipyrromethane units are linked via C-C double bonds. One of them, calix[2]bispyrrolylethene, colorimetrically senses fluoride ion only, owing to anion-π interaction in polar aprotic solvents.

Chemoselective Carbene insertion into the N–H Bond over O–H Bond Using a Well-Defined Single Site (P–P)Cu(I) Catalyst

Phosphine-coordinated air-stable Cu(I) catalyst (1) has been synthesized and characterized. Catalyst 1 is found to be active toward highly chemoselective carbene insertion into the N-H bond over the O-H bond and also over the formation of olefins when numerous aminophenols were treated with a variety of α-aryl diazoesters under normal experimental conditions.

Synthesis of Aminobenzoic Acid Derivatives via Chemoselective Carbene Insertion into the −NH Bond Catalyzed by Cu(I) Complex

Phosphine ligand stabilized air-stable Cu(I) complexes have been successfully used to functionalize the aromatic aminobenzoic acids in a chemoselective manner without implementing protection and deprotection strategy under mild reaction conditions. This chemoselective carbene insertion into -NH bond over -COOH and -OH bonds leads to the wide range of carboxy and hydroxy functionalized α-amino esters (27 examples). All of the isolated new products have been fully characterized using standard analytical methods.

Hydrogenation of dinitrogen to ammonia in [WF(PH2(CH2)2PH2)2N2] using H2: Insights from DFT calculations

A new methodology has been proposed to reduce the molecular dinitrogen to ammonia in [WF(PH2(CH2)2PH2)N2] (1) and tested for thermodynamic feasibility by DFT calculations in three different solvents. The calculated barriers for 1 revealed that N2 can be reduced by H2 in organic solvents.

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

AbstractAtmospheric N2 can be cleaved directly to yield metal-nitride (before proceeding to the functionalization of Nα 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. Graphical AbstractN2 can be cleaved directly to form nitride complex and subsequently can be converted to ammonia in the presence of protons and electrons using M(III)(NMe2)3 (M = Mo/W) in a homogeneous solution under normal experimental conditions. The proposed pathway seems to be feasible based on the calculated thermodynamic and kinetic barriers.

A [Fe(CB6)] platform for binding of small molecules: Insights from DFT calculations

The viability of making [Fe(CB6)L] (L = H2, N2, O2, nitric oxide [NO−, NO, and NO+], CO2, and hydrocarbons [CH4, C2H6, C2H4, and C6H6]) has been investigated by density functional theory (DFT) calculations. The complexes 2–18 are thermodynamically stable and may be synthesized. The small molecules are activated to some extent after complexation. Molecular orbital and ΔG calculation revealed that the molecular hydrogen and hydrocarbons can be chemically adsorbed and desorbed on [Fe(CB6)] without any significant chemical modification and therefore [Fe(CB6)] may serve as a storage material. The N2, O2, and nitric oxide (NO−, NO, and NO+) can be activated using [Fe(CB6)]. Proton, carbon, boron, and nitrogen NMR chemical shift calculation predicts drastic chemical shift difference before and after the complexation of [Fe(CB6)] with small molecules. This new findings suggest that the CB62− ligand‐based complex may provide several applications in the future.