MOLECULAR INTERACTION BETWEEN BENZONITRILE AND HEXAMETHYLPHOSPHORIC TRIAMIDE BY ¹³C NMR T₁ RELAXATION TIME STUDIES AND AB INITIO QM CALCULATIONS: EXTENDED INVESTIGATION

• Main Authors: Parsaoran Siahaan, Cynthia L. Radiman, Susanto Imam Rahayu, Muhamad A. Martoprawiro, Dieter Ziessow
• Format: Article
• Language: English
• Published: Universitas Gadjah Mada 2010-06-01
• Series: Indonesian Journal of Chemistry
• Online Access: https://jurnal.ugm.ac.id/ijc/article/view/21544

It has been obtained the anisotropy ratio a = T1(ortho-,meta-13C)/T1(para-13C) of dilute solutions of bn change from 1.7 in fa solution and 1.5 in neat bn to 1.0 in HMPT. Thus the anisotropy ratio comes out to be a = 1. In HMPT, obviously, solvent molecules cluster around Ph-CºN in such a way, that non-covalent interactions lead to isotropic reorientational motion like a spherical molecule. To conform with the T1 times, a layer arrangement with at least two HMPT molecules per Ph-CºN seems to be likely. From computational quantum calculations of non-covalent intermolecular interactions and Mie potential analysis, the solute-solvent molecular pairs in  bnּּּHMPT have almost equal interaction energies for the ortho, meta, and para configuration and the layered configurations are energetically permitted    Keywords: 13C T1 spin-lattice relaxation times, ab initio quantum chemistry calculations, intermolecular interactions,  isotropic and anisotropic rotational motion