title: Classification of the hydrogen-bonding species in a series of novel hydrazide based azobenzene derivatives investigated by two-dimensional correlation infrared spectroscopy and molecular modeling.
abstract: Classification of hydrogen-bonding species in a series of novel hydrazide modified p-methoxyazobenzene derivatives, 4-{n-[4-(4-methoxy-phenylazo)-phenoxy]-alkoxy}-benzoic acid hydrazide (Dn, n = 3, 6, 10) are performed in the present study. Temperature-dependent infrared (IR) spectra of Dn have been measured to investigate the thermal stability of the weak intermolecular interactions, such as hydrogen bonding among hydrazide moieties, pi-pi stacking among aromatic groups, and hydrophobic interaction between alkyl chains. In order to reveal the hydrogen bonding formed between NH, NH2, and CONH groups efficiently, two-dimensional (2D) correlation spectra have been constructed in the thermal sensitive spectral regions of (a) 3500-3100 cm(-1) and (b) 1700-1450 cm(-1), separately, and it have also been constructed between these two spectral regions. Based on the experimental data, the ab initio computational models have been developed to the proposed patterns of hydrogen bonding related to intermolecular interactions in Dn. The intermolecular hydrogen bondings and molecular alignments patterns result from both the experimental data and the computational models are performed for D3, D6, and D10, respectively, in the present study.
authors.affiliation: Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Jilin 130012, PR China.
authors.forename: Hai-Hao
authors.initials: HH
authors.lastname: Zhang
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wu
authors.forename: Bing-Lian
authors.initials: BL
authors.lastname: Bai
authors.forename: Min
authors.initials: M
authors.lastname: Li
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D013055:Spectrophotometry, Infrared; D013696:Temperature
chemical_list: C508921:4-(n-(4-(4-methoxyphenylazo)phenoxy)hexoxy)benzoic acid hydrazide; C508920:4-(n-(4-(4-methoxyphenylazo)phenoxy)propoxy)benzoic acid hydrazide; D001391:Azo Compounds; D006834:Hydrazines; C508922:t4-(n-(4-(4-methoxyphenylazo)phenoxy)decoxy)benzoic acid hydrazide; C009850:azobenzene