Molecular Structure And Vibrational and Chemical Shift Assignments of Cis-1,2-Dihydroxy-Trans-3-Methoxy-1,5,5-Trimethylcyclohexane and Cis-2,3-Dihydroxy-Trans-1-Methoxy-1,5,5-Trimethylcyclohexane By Dft and Ab Initio Hf Calculations

Abstract

The molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1H NMR and 13C NMR chemical shift values and several thermodynamic parameters of cis-1,2-dihydroxy-trans-3-methoxy-1,5,5-trimethylcyclohexane (6) and cis-2,3-dihydroxy-trans-1-methoxy-1,5,5-trimethylcyclohexane (7) in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. In addition, calculated results were related to the linear correlation plot of experimental 1H NMR and 13C NMR chemical shifts values.

cis- 1,2-dihidroksi-trans-3-metoksi-1,5,5-trimetilsiklohekzana ve cis- 2,3-dihidroksi-trans-1-metoksi-1,5,5-trimetilsiklohekzan moleküllerinin gometrik titreşim frekansları, atomik orbitalleri içeren (GIAO) 1H ve 13C NMR kimyasal kaymaları ve birçok termodinamik parametreleri yoğunluk fonsiton teorisi(DFT) ve ab initio HF yöntemleri ve 6-31g(d) temel şefi kullanılarak hesaplandı. Kararlı hale getirilmiş molekül yapısı ile deneysel x-ışınları spektrumu karşılaştırıldı. Teorik olarak hesaplanan titreşim frekansları ile deneysel titreşim frekansları karşılaştırıldı. İlave olarak hesaplanan sonuçlar ile deneysel 1H ve 13C NMR sonuçlarına uygunluk grafikleri çizildi.