title: Enhanced third-order nonlinear optical properties determined in thin films using the Z-scan technique: bis(μ-4,4'-oxydibenzoato)bis[(4'-phenyl-2,2':6',2''-terpyridine)cobalt(II)].
abstract: π-Conjugated organic materials exhibit high and tunable nonlinear optical (NLO) properties, and fast response times. 4'-Phenyl-2,2':6',2''-terpyridine (PTP) is an important N-heterocyclic ligand involving π-conjugated systems, however, studies concerning the third-order NLO properties of terpyridine transition metal complexes are limited. The title binuclear terpyridine Co(II) complex, bis(μ-4,4'-oxydibenzoato)-κ(3)O,O':O'';κ(3)O'':O,O'-bis[(4'-phenyl-2,2':6',2''-terpyridine-κ(3)N,N',N'')cobalt(II)], [Co2(C14H8O5)2(C21H15N3)2], (1), has been synthesized under hydrothermal conditions. In the crystal structure, each Co(II) cation is surrounded by three N atoms of a PTP ligand and three O atoms, two from a bidentate and one from a symmetry-related monodentate 4,4'-oxydibenzoate (ODA(2-)) ligand, completing a distorted octahedral coordination geometry. Neighbouring [Co(PTP)](2+) units are bridged by ODA(2-) ligands to form a ring-like structure. The third-order nonlinear optical (NLO) properties of (1) and PTP were determined in thin films using the Z-scan technique. The title compound shows a strong third-order NLO saturable absorption (SA), while PTP exhibits a third-order NLO reverse saturable absorption (RSA). The absorptive coefficient β of (1) is -37.3 × 10(-7) m W(-1), which is larger than that (8.96 × 10(-7) m W(-1)) of PTP. The third-order NLO susceptibility χ((3)) values are calculated as 6.01 × 10(-8) e.s.u. for (1) and 1.44 × 10(-8) e.s.u. for PTP.
authors.affiliation: School of Resources and Environmental Science, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China.
authors.forename: Runqiang
authors.initials: R
authors.lastname: Liu
authors.affiliation: School of Resources and Environmental Science, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhao
authors.affiliation: School of Resources and Environmental Science, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China.
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.affiliation: School of Resources and Environmental Science, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China.
authors.forename: Caixia
authors.initials: C
authors.lastname: An
authors.affiliation: School of Resources and Environmental Science, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang, Henan 453003, People's Republic of China.
authors.forename: Zhaoxun
authors.initials: Z
authors.lastname: Lian
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D008958:Models, Molecular; D055095:Optics and Photonics; D011725:Pyridines / Q000737:chemistry*
chemical_list: C517923:(2,2'-6',2'')-terpyridine; C539796:4,4'-oxydibenzoic acid; D001565:Benzoates; D056831:Coordination Complexes; D008024:Ligands; D011725:Pyridines; D003035:Cobalt
keywords: Z-scan technique; binuclear cobalt(II) complex; crystal structure; optical materials; terpyridine cobalt(II) complex; thin film; third-order nonlinear optical properties