Search

This paper describes the rare use of a 6‐membered saturated N‐heterocyclic carbene (NHC) known as 1,3‐di(2,6‐diisopropylphenyl) tetrahydropyrimidine‐2‐ylidene (abbreviated as 6‐SIDipp) as a ligand in zinc chemistry. We report on the investigation of the reactions between 6‐SIDipp and ZnX2, which resulted in a range of new monomeric 6‐SIDipp⋅ZnX2 complexes (X=Et (1), Cl (2), Br (3), and I (4)). We also prepared a new NHC zinc complex where the two substituents of the zinc atom are different, 6‐SIDipp⋅Zn(Et)Br (7) through the reaction of the proligand [6‐SIDippH]Br with ZnEt2. We have observed that the reactions of complex 1 with sulfur and HBpin led to the removal of the ZnEt2 moiety, resulting in the formation of a C=S double bond and a B−H activation product, respectively. Lastly, the reaction of 1 with five‐membered NHCs led to the exchange of carbene and the formation of either 5‐IDipp⋅ZnEt2 (8) or 5‐SIDipp⋅ZnEt2 (9). [ABSTRACT FROM AUTHOR]

A glycerol‐triazole tethered rhodamine based colorimetric and fluorimetric sensor 3′,6′‐bis(diethylamino)‐2‐(((1‐(1,3‐dihydroxypropan‐2‐yl)‐1H‐1,2,3‐triazol‐4‐yl)methylene)aminospiro [isoindoline‐1,9′‐xanthen]‐3‐one (L1) is designed and synthesized for the selective recognition of Cu2+ ion. The sensor L1 allows naked eye detection of Cu2+ ion with a fast response (<1 min). Among the various metal ions tested, the sensor L1 shows selective binding with Cu2+ through turn‐on fluorescence mechanism. The sensor shows 1 : 2 binding stoichiometry with binding constant, Ka=1.1×106 M−2 as revealed by job's plot & Benesi‐Hildebrand plot (B−H plot), respectively. The detection limit of L1 with Cu2+ ion is found to be 3.3 μM. Further, the experimental results are also validated using density functional theoretical (DFT) study. The optimized geometries indicates that the formation of the L1‐Cu2+ complex is thermodynamically favourable by ΔG=−11.7 kcal/mol. The HOMO‐LUMO gap of the ligand L1 is found to be 3.49 eV, which decreases to 1.76 eV upon complexation with copper. [ABSTRACT FROM AUTHOR]

A glycerol‐triazole tethered rhodamine based colorimetric and fluorimetric sensor 3′,6′‐bis(diethylamino)‐2‐(((1‐(1,3‐dihydroxypropan‐2‐yl)‐1H‐1,2,3‐triazol‐4‐yl)methylene)aminospiro [isoindoline‐1,9′‐xanthen]‐3‐one (L1) is designed and synthesized for the selective recognition of Cu2+ ion. The sensor L1 allows naked eye detection of Cu2+ ion with a fast response (<1 min). Among the various metal ions tested, the sensor L1 shows selective binding with Cu2+ through turn‐on fluorescence mechanism. The sensor shows 1 : 2 binding stoichiometry with binding constant, Ka=1.1×106 M−2 as revealed by job's plot & Benesi‐Hildebrand plot (B−H plot), respectively. The detection limit of L1 with Cu2+ ion is found to be 3.3 μM. Further, the experimental results are also validated using density functional theoretical (DFT) study. The optimized geometries indicates that the formation of the L1‐Cu2+ complex is thermodynamically favourable by ΔG=−11.7 kcal/mol. The HOMO‐LUMO gap of the ligand L1 is found to be 3.49 eV, which decreases to 1.76 eV upon complexation with copper. [ABSTRACT FROM AUTHOR]

Our study introduces the design of inverse sandwich (iSw) complexes incorporating a noble gas compound: xenon trioxide (XeO 3 ). Through comprehensive computational analyses, we have investigated the critical factors influencing their stability by employing a variety of state-of-the-art computational tools. We demonstrated that the coordination number of xenon in the iSw complex of XeO 3 with 18-crown-6 is influenced by the presence of a rare, weakly stabilizing Xe···Xe interaction between the XeO 3 molecules. Furthermore, we observed that the stability of iSw complexes of 1,3,5-triphenylbenzene (TPB) and its derivatives is not solely attributed to aerogen bonding, but also involves contributions from C-H···O interactions and back-donation from the lone pair of Xe to the antibonding C-C orbitals of TPB. Additionally, the significant contributions from orbital interactions and dispersion interactions in the TPB derivatives highlight the multifaceted amphoteric properties of XeO 3 and reveal that the iSw complexes of TPB and derivatives are not predominantly governed by electrostatic interactions, contrary to conventional belief.

In order to control the explosiveness and shock sensitivity of XeO 3 , we have investigated its plausible interaction with various non-aromatic coordinating solvents, serving as potential Lewis base donors, through density functional theory (DFT) calculations. Out of twenty six such solvents, the top ten were thus identified and then thoroughly examined by employing various computational tools such as the mapping of the electrostatic potential surface (MESP), Wiberg bond indices (WBIs), non-covalent interaction (NCI) plots, Bader's theory of atoms-in-molecules (AIM), natural bond orbital (NBO) analysis, and the energy decomposition analysis (EDA). The amphoteric nature of XeO 3 was also explored by investigating the extent of back donation from the lone pair of Xe to the antibonding orbital of the donating atom/group of the solvent molecules. The C-H…O interactions were also found to be a contributing factor in the stabilization of these adducts. Although these aerogen-bonding interactions were found to be predominantly electrostatic, significant contributions from the orbital contributions, as well as dispersion interactions, were observed. The top three non-aromatic solvents (among the twenty six studied) which form the strongest adducts with XeO 3 are proposed to be hexamethylphosphoramide (HMPA), N,N'-dimethylpropyleneurea (DMPU) and tetramethylethylenediamine (TMEDA)., (© 2024 Wiley-VCH GmbH.)

A series of Cu-Ag bimetal alloys decorated on SiO 2 and the fabrication of few-layer S-doped graphitic carbon nitride (SC) warped over it to form a core-shell nanostructured morphology have been demonstrated and well characterized through various physiochemical techniques. HRTEM data confirmed the formation of a compact nanojunction between the SiO 2 and SC, where Cu-Ag is embedded uniformly with an average particle size of 1.3 nm. The Ag : Cu (1 : 3) between SiO 2 and SC produces 1730 μmol h -1 g -1 of H 2 under visible light illumination. Moreover, 6.2-fold current enhancement in the case of Ag : Cu (1 : 3) as compared to the Ag-loaded core-shell nanostructured photocatalyst indicates higher electron-hole-pair separation. The excellent activity was due to the synergistic alloying and plasmonic effect of Ag and Cu. DFT studies reveal that the Cu atom in the Cu-Ag bimetal alloy plays a pivotal role in the generation of H 2 , and the reaction proceeds via a 4-membered transition state. The mechanistic insight proceeds from the generation of hot electrons due to the LSPR effect and their transfer to the SC layer via a compact nanojunction., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)