COMPARATIVE STUDY BETWEEN OF RELATIONSHIP OF RRM AND SHUSTER METHODS WITH GEOMETRICAL PARAMETERS ON THE DICARBALDEHYDE PHOSPHHINE COMPOUND IN GAS PHASE

Comparative study between of relationship of RRM and Shuster methods and geometrical parameters on the Dicarbaldehyde phoshine compound in gas phase P. Mohammadzadeh Jahania*, H. Hamidianb, A. Fadakarc, a*Department of medicine, Bam university of medical science, Bam, Iran b,cDepartment of Chemistry, Payam Noor University. P.O. Box 19359-4697, Tehran, Iran Corresponding author. Email mjpeyman@yahoo.com Keywords: Intermolecular hydrogen bonding, Dicarbaldehyde phoshine, AIM Introduction: In order to investigation of P-heteroatom effects on the nature of O-H…O intramolecular hydrogen bond (IMHB) on Dicarbaldehyde phoshine (DCP) and its derivatives calculations in gas phase were performed and their IMHB energies were obtained using the shuster and Related Rotomer (RRM) methods.[1,2] Also the geometrical parameters such as RO-H, RO…O and RO…H were gained from output files of Gaussian 09 series of programs . Methods: All of calculations were performed by Gaussian 09 series of programs. The geometry optimizations were carried out by MP2 method. The nature of the IMHB in the chelated forms has been studied using the AIM theory by means of AIM2000 software.[3] Results and discussion: In this study, IMHB energies of DCP and its halogen derivatives have been evaluated by RRM and Shuster methods. R1,R2 E Shuster E RRM RO…H H , H 29.95 43.03 1.702 Br, H 26.06 41.02 1.713 Cl , H 23.88 66.16 1.601 F, H 24.19 113.15 1.582 NH2, H 21.56 49.09 1.667 NO2 ,H 15.33 37.54 1.724 There are two different situations (R1 and R2) for halogen substitution in RAHB ring of DCP. (Fig. 1) From the results shown in table we can conclude that RRM energy strongly correlates with RO-H, RO…O and RO…H. Conclusions: Linear relationship between RRM energy and geometrical parameters not only reveals that the RRM energy is a good measure of IMHB energy but also suggest that these parameters and corresponding equations can be used for estimating the IMHB energy in different systems as bio macromolecules. Furthermore, it was found that the shuster hydrogen bond energies cannot represent good linear correlations with these parameters. References: [1]. P. Schuster, G. Zundel, The Hydrogen Bond, Recent Development in Theory and experiment; North-Holland: Amsterdam, NL, 1976. [2]. M.Jablonski, A. Kaczmarek, A. J. Sadlej. J Phys Chem 2006, 110A, 10890. [3]. F. Biegler-König, J, D. Schönbohm, A. Bayles, and Aim2000: Program To Analyze And Visualize Atoms In Molecules, University Of Applied Science, Bielefeld Germany, 2000.