Strongly luminescent metal–organic compounds: spectroscopic properties and crystal structure of substituted 1,8-naphthyridine and its zinc(II) complex

Abstract

N,N@-Bisbenzyl-2,7-diamino-1,8-naphthyridine (L) and its zinc (II) complex, are strongly [Zn(L) 2 (OAc) 2 ], luminescent materials with emission quantum yields in methanol being 0.38 and 0.59, respectively. The crystal structure of features a one-dimensional chain structure through intermolecular pÈp stacking [Zn(L) 2 (OAc) 2 ] interactions. A broad emission band ranging from 400 to 600 nm is observed from the solid at [Zn(L) 2 (OAc) 2 ] room temperature.

2D Molecular Square Grid with Strong Blue Fluorescent Emission: A Complex of Norfloxacin with Zinc(II)

“…The most important feature of the structure of 1 is the 2D condensed polymeric structure, and this unique structure perhaps leads to significant enhancement of fluorescent intensity which is almost 2−3 times larger than that of free H-Norf, probably due to coordination of H-Norf to Zn(II) increasing the ligand conformational rigidity, thereby reducing the nonradiative decay of the intraligand 1 (π−π*) excited state. Similar enhancement of the intraligand fluorescence has also been reported for [ Zn(terpyridine) 2 ] 2+ and [Zn(L) 2 (OAc) 2 ] (L = N , N ‘-bisbenzyl-2,7-diamino-1,8-naphthyridine) . The solid state diffuse reflectance UV−vis spectra of 1 and 2 show two intense bands at 339.8 and 281.5 nm for 1 and 344.3 and 272.5 nm for 2 , respectively, which are assigned to the intraligand π−π* transition of H-Norf (329.9 and 278.1 nm) and match well with excitation spectra of 1 , 2 , and free ligand (λ max = 350 nm).…”

“…Wang and co-workers recently reported several new types of blue luminescent coordination and organometallic compounds . We have also prepared several blue luminescent organic−inorganic hybrid coordination polymers . To this end, we have performed the two hydrothermal reactions of norfloxacin (H-Norf) with Zn(OH) 2 and Zn(NO 3 ) 2 ·6H 2 O, respectively.…”

Syntheses, Structures, and Photoluminescence Properties of Metal(II) Halide Complexes with Pyridine-Containing Flexible Tripodal Ligands

“…For complexes 5 , 6 , and 7 , blue emissions with maxima at 450, 452, and 457 nm were observed upon excitation at 396 nm, while free ligand L 4 displays an emission maximum at 420 nm under the same conditions. The observed emissions of complexes 1 , 2 , 5 , 6 , and 7 are probably contributed by the π−π* intraligand fluorescence since similar emissions were also observed for the ligands themselves . The observed red or blue shift of the emission maximum between the complexes and the corresponding ligand was considered to mainly originate from the influence of the coordination of metal atom to the ligand.…”

Synthesis and characterization of a novel 2D zinc(II) coordination polymer

“…S4 (see Supplementary material), the solidstate fluorescent spectra of the ligand 5-[ 2 H 7 ]tolyl-1H-tetrazole, [Zn(4-MPTZ) 2 ] and the compound 1 at room temperature reveal maximal emission peaks at 408, 413 and 413 nm, respectively [25]. The enhanced luminescence efficiency (with the excited radiation setting at 352 nm) and slight red shift are attributed to the coordination of the ligands to zinc to result in the effective increase of the rigidity of the ligand and the reduction of energy loss via radiation-less decay of the intraligand emission excited state [26,27].…”