title: Molecular spectrum of lanthanide complexes with 2,3-dichlorobenzoic acid and 2,2-bipyridine.
abstract: With 2,3-dichlorobenzoic acid as the first ligands and 2,2'-bipyridine as the second ligands, the lanthanide complexes [Ln(2,3-DClBA)3bipy]2 [Ln=Nd(a), Sm(b), Eu(c), Tb(d), Dy(e), Ho(f)] have been synthesized. By using Infrared (IR) and Raman (R) spectra, the characteristics of the groups can be identified. The bands of lanthanide complexes have been analyzed and attributed, and clearly demonstrated with the use of the complementarity of IR and R. The experiment reveals that the bands of complexes are affected by lanthanide elements (Ln). The frequency of stretching vibration and breathing vibration of ring, together with the stretching vibration of the carbonyl group (νCO), tends to be rising as the atomic number of lanthanide increasing. Meanwhile, crystallography data demonstrate that the six carbonyl groups have different bond length and bond angle, which can lead to different vibration frequency. The second derivatives of IR show that there are multiple vibration frequencies existing in the symmetrical stretching vibration of the carbonyl group (νsCO). Therefore the second derivative of IR spectrum is a characteristic band of different coordination modes of carbonyl group.
authors.affiliation: Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024, PR China. Electronic address: hsm63@163.com.
authors.forename: Shu-Mei
authors.initials: SM
authors.lastname: He
authors.affiliation: No.1 High School of Dezhou, Dezhou 253000, PR China.
authors.forename: Shu-Jing
authors.initials: SJ
authors.lastname: Sun
authors.affiliation: Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024, PR China.
authors.forename: Jun-Ru
authors.initials: JR
authors.lastname: Zheng
authors.affiliation: Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024, PR China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Zhang
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D002723:Chlorobenzoates / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008958:Models, Molecular; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D002723:Chlorobenzoates; D056831:Coordination Complexes; D028581:Lanthanoid Series Elements; C070735:2,4-dichlorobenzoic acid; D015082:2,2'-Dipyridyl
keywords: FT-IR; FT-Raman; Lanthanide complexes; Second derivative; Vibrational assignment