Reaction-controlled assemblies and structural diversities of seven Co(ii)/Cu(ii) complexes based on a bipyridine-dicarboxylate N-oxide ligand

Highly Thermally and Chemically Stable Nickel(II) Coordination Polymers: Tentative Studies on Their Sorption, Catalysis, and Magnetism

“…The separation of 241 cm –1 (for 1 ), 251 cm –1 (for 2 ), and 233 cm –1 (for 4 ) between these two bands (ν as (COO – ) – ν s (COO – )) is typical of a monodentate coordination of a carboxylate group. , Δν = 186 ( 3 ), 170 cm –1 ( 5 ) are assigned to the stretching modes of the chelating carboxylate. For 4 , the existence of a medium-intensity peak at 1705 cm –1 attributable to the CO vibration of the −COOH group confirms the partial deprotonation of the dicarboxylic ligand. , Furthermore, the sharp absorption bands at 1543–1545 and 1445–1460 cm –1 correspond to the characteristic absorptions of the CC and CN bonds in benzimidazole, respectively. Bands in the absorption region of 600–1300 cm –1 stemming from N-donor ligands, viz.…”

“…For 4, the existence of a mediumintensity peak at 1705 cm −1 attributable to the CO vibration of the −COOH group confirms the partial deprotonation of the dicarboxylic ligand. 58,59 Furthermore, the sharp absorption bands at 1543−1545 and 1445−1460 cm −1 correspond to the characteristic absorptions of the CC and CN bonds in benzimidazole, respectively. Bands in the absorption region of 600−1300 cm −1 stemming from N-donor ligands, viz.…”

Comparative Study of Structures and Luminescent Properties of Three Ag(I) Complexes Utilizing an Achiral Bipyridyl-N or Its Axially Chiral N-Oxide Analogue

“…The (R,S)-H 2 L NO is prepared in the light of the reported works. 18 And all the solvents and reagents employed in this work are purchased and they need not further treatment. Infrared spectra are measured with KBr pellets on a Nicolet Avatar 360 FTIR spectrometer (4000−400 cm −1 ).…”

“…The ( R , S )-H 2 L NO is prepared in the light of the reported works . And all the solvents and reagents employed in this work are purchased and they need not further treatment.…”

“…The ( R , S )-2,2′-bipyridyl-3,3′-dicarboxylate-1,1′-dioxide (( R , S )-H 2 L NO ) with an N -oxide group, a good candidate ligand for building complexes with attractive structures and multitude properties, ,− is employed in our previous study to investigate the complexes’ structure–property relationships. , Such ( R , S )-H 2 L NO can be obtained by oxidizing the 2,2′-bipyridyl-3,3′-dicarboxylate (H 2 L N ). , As shown in Scheme , the brilliant oxidation of the bipyridyl- N into bipyridyl N -oxide brings a series of changes: (1) pyridine- N becomes a charge-separated N -oxide group; (2) the coordination modes become more versatile due to that the N -oxide donor possesses two lone pairs of electrons in different orientations while N has one pair (Figure S1a,b); ,,, (3) the borderline bases pyridyl- N turn into hard O donors; and (4) the conformations of ligands vary from achiral H 2 L N to C 2 axially chiral ( R , S )-H 2 L NO .…”