作者:Chun-Hua Huang、Mingxue Yang、Xu-Lin Chen、Can-Zhong Lu
DOI:10.1039/d0dt04424e
日期:——
emission decay behaviors, reveal that the title Cu(I) complexes emitefficientthermallyactivateddelayedfluorescence (TADF) from excited states involving metal-to-ligand charge transfer (MLCT) transitions and ligand-to-ligand charge transfer (LLCT) transitions. The emissive-state characteristics and emission properties of the investigated Cu(I) complexes were tuned effectively by changing the steric
Reaction of the ligands 3-phenyl-5-(2-pyridyl)pyrazole (HL0) and 3-phenyl-5-(6-methyl-(2-pyridyl))pyrazole (HL1) with Cu(NO3)(2). 3H(2)O and CuX2. xH(2)O (X = Cl, Br) gives complexes with stoichiometry Cu(HL0)(2)X-2. xH(2)O, Cu(HL1)(2)X-2. EtOH, Cu(HL)X-2, Cu(HL)(2)(NO3)(2). xH(2)O (HL = HL0, HL1) and Cu(HL0)(NO3)(2). 2H(2)O. The new complexes were characterised by elemental analyses, conductivity measurements and infrared and electronic spectroscopy. The crystal and molecular structure of [Cu(HL0)(NO3)(H2O)(2)](NO3) consists of discrete cations and NO3 anions linked by hydrogen bonds. The cation complex [Cu(HL0)(NO3)(H2O2)(2)](+) contains a copper(II) with a distorted tetragonal pyramid geometry (tau = 0.094), with a H2O ligand occupying the apical site. The penta-coordinated metal atom is bonded to one pyridinic nitrogen, one pyrazolic nitrogen, one nitrate and two water molecules. The ligand HL0 is not completely planar. (C) 2001 Elsevier Science Ltd. All rights reserved.
Ni(II) complexes with pyrazole-derived ligands. Crystal structures of [Ni(HL0)2ClH2O][Ni(HL0)2(H2O)2]Cl3·CH3OH·H2O and [Ni(HL1)2(H2O)2]Br2·2.5DMF (HL0=3-phenyl-5-(2-pyridyl)pyrazole and HL1=3-phenyl-5-(6-methyl-(2-pyridyl))pyrazole
The reaction of 3-phenyl-5-(2-pyridyl)pyrazole (HL0) and 3-phenyl-5-(6-methyl-(2-pyridyl))pyrazol (HL1) with nickel(II) salts produces mononuclear coordination compounds. The new complexes have been characterised by elemental analyses, conductivity measurements and infrared and electronic spectroscopies.Two different forms of mononuclear nickel(II) complexes have been prepared and structurally characterised by X-ray crystallography: [Ni(HL0)(2)Cl(H2O)][Ni(HL0)(2)(H2O)(2)]Cl-3. CH3OH .H2O [Ni(HL1)(2)(H2O)(2)]Br-2.2.5DMF. In the cationic com plexes, the coordination of the Ni(II) is octahedral with two bidentate HL0 or HL1 neutral ligands in a cis disposition. The degree of distortion from regular octahedral geometry is compared to closely related structures. In the solid state, cations and anions are bonded by hydrogen bonding. (C) 2001 Elsevier Science Ltd. All rights reserved.
Cobalt(II) complexes with pyrazole-derived ligands: crystal structure of {bis[3-phenyl-5-(2-pyridyl) pyrazole]aquachlorocobalt(II)}chloride monohydrate
The synthesis of the new pyrazole-derived ligands 3-phenyl-5-(2-pyridyl) pyrazole (HL0) and 3-phenyl-5-(6-methyl-(2-pyridyl))pyrazole (HL1) and their Co(II) complexes is reported. Elemental analyses, conductivity measurements and IR and UV-Vis spectroscopies defined all complexes. H-1 and C-13 NMR spectroscopies were also used in the characterization of ligands. The crystal and molecular structures of [Co(HL0)(2)Cl(H2O)] Cl . H2O, consisting of discrete ions and water molecules linked by hydrogen bonds, are also reported. The hexacoordinated metal atom is bonded to two pyridinic nitrogens, two pyrazolic nitrogens tone of each nitrogen belonging to two different ligands), one chlorine atom and one water molecule, forming a distorted octahedral environment. The ligands are not exactly planar and the arrangement of ligands is cis, with a dihedral angle between the two mean planes of ligands of 89.21(6)degrees. The degree of distortion from regular octahedral geometry is compared to that of closely related structures. (C) 2000 Elsevier Science Ltd All rights reserved.
Complexes of Cu(II), Co(II) and Ni(II) with pyrazole-derived ligands. Crystal structure of {bis[3-phenyl-5-(2-pyridyl)pyrazolato, κN1:κN2]copper(II)}
The reaction of the pyrazole derived-ligands 3-phenyl-5-(2-pyridyl)pyrazole (HL0) and 3-phenyl-5-(6-methyl-2-pyridyl)pyrazole (HL1) with Cu((CHCOO)-C-3)(2), Co(CH3COO)(2) and Ni(CH3COO)(2) was carried out. Products were characterised by elemental analyses, conductivity measurements and infrared and electronic spectroscopy. The IR spectra of complexes display the typical absorption bands of pyrazole-derived ligands. The nature of the complexes depends on the metal. M, the ligand, HL, and the M:HL ratio: Ni(HL)(2)(CH3COO)(2), Cu(L)(2), (HL = HL0, HL1), Co(L-0)(2). In the complexes of Co(II) and Cu(II) the pyrazole is deprotonated, the band nu (N-H) was not observed in IR spectroscopy. The crystal structure of [Cu(L-0)(2)] consists of discrete centrosymmetric molecules involving a co-ordinated CuN(pz)(2)N(py)(2) core with planar geometry. The anionic ligand L-0 is not completely planar. (C) 2001 Elsevier Science B.V. All rights reserved.