CuN4O2 Chromophore Research Articles

Crystal structure of mixed-ligand copper(II) complexes. Bis(2,2′-bipyridyl)monophenylphos-phatocopper(II)monophenylphosphate monohydrate, [Cu(C10H8N2)2(C6H5OPO3)]-(C6H5OPO3H2)(H2O)

The title mixed-ligand copper(II) complex has been synthesized and its crystal structure at room temperature solved. The crystals are monoclinic:P21/c,a=12.004(3),b=19.402(5),c=14.192(4) A,β=108.80(3)°,Z=4. The structure was solved by direct methods, and refined to anR value of 0.041 for 4457 nonzero independent reflections. The crystal structure consists of discrete [Cu(bipy) (MPhP)] units, noncoordinated MPhPH2, and H2O molecules. Each [Cu(bipy)2(MPhP)] unit involves a five coordinate CuN4O chromophore with a distorted trigonal-bipyramidal stereochemistry. The phosphate groups are linked together by short hydrogen bonds of (P)-O-H-⋯-O-P type.

ChemInform Abstract: THE CRYSTAL STRUCTURE AND ELECTRONIC PROPERTIES OF THE COMPLEXES ACETATOBIS(1,10‐PHENANTHROLINE)COPPER(II) PERCHLORATE DIHYDRATE, ACETATOBIS(1,10‐PHENANTHROLINE)COPPER(II) NITRATE DIHYDRATE, AND ACETATOBIS(1,10‐PHENANTHROLINE)ZINC(II) TETRAFLUOROBORATE DIHYDRATE

The crystal structure of [Cu(phen)2(O2CMe)][ClO4]·2H2O (1), [Cu(phen)2(O2CMe)][NO3]·2H2O (2), and [Zn(phen)2(O2(CMe)][BF4]·2H2O (3) have been determined by X-ray analysis. Complex (1) crystallises in the monoclinic space group P2/c with a= 9.671(3), b= 8.282(3), c= 17.595(4)A, β= 109.63(2)°, and Z= 2; (2) crystallises in the triclinic space group P with a= 14.728(2), b= 10.499(2), c= 8.603(2)A, α= 104.19(5), β= 83.97(5), γ= 96.81(5)°, and Z= 2;(3) crystallises in the monoclinic space group P2/c with a= 9.659(2), b= 8.262(2), c= 17.651(2)A, β= 109.06(5)°, and Z= 2. The MN4O2 chromophore in all three complexes has a cis-octahedral stereochemistry. In (1) and (3) the metal atoms have C2 symmetry and in (1) there is a marked cis distortion of the Cu–O distances. In (2) a distortion of the CuN4O2 chromophore towards a square pyramidal (4 + 1 + 1*) stereochemistry is present. The polycrystalline e.s.r. spectra of (1) and (2) and of 10% copper(II)-doped (3) are temperature variable, consistent with a fluxional CuN4O2 chromophore stereochemistry. The temperature variability of the single-crystal e.s.r. spectra of (1), (2), and copper(II)-doped (3) is restricted to the CuN2O2 plane, consistent with two-dimensional fluxional behaviour. The electronic reflectance spectra of (1) and (2) involve two peaks at ca. 10 000 and ca. 14 000 cm–1 and relate to the underlying static CuN4O2(4 + 1 + 1*) chromophore stereochemistry.

The crystal structure and electronic properties of the complexes acetatobis(1,10-phenanthroline)copper(II) perchlorate dihydrate, acetatobis(1,10-phenanthroline)copper(II) nitrate dihydrate, and acetatobis(1,10-phenanthroline)zinc(II) tetrafluoroborate dihydrate

The crystal structure of [Cu(phen)2(O2CMe)][ClO4]·2H2O (1), [Cu(phen)2(O2CMe)][NO3]·2H2O (2), and [Zn(phen)2(O2(CMe)][BF4]·2H2O (3) have been determined by X-ray analysis. Complex (1) crystallises in the monoclinic space group P2/c with a= 9.671(3), b= 8.282(3), c= 17.595(4)Å, β= 109.63(2)°, and Z= 2; (2) crystallises in the triclinic space group P with a= 14.728(2), b= 10.499(2), c= 8.603(2)Å, α= 104.19(5), β= 83.97(5), γ= 96.81(5)°, and Z= 2;(3) crystallises in the monoclinic space group P2/c with a= 9.659(2), b= 8.262(2), c= 17.651(2)Å, β= 109.06(5)°, and Z= 2. The MN4O2 chromophore in all three complexes has a cis-octahedral stereochemistry. In (1) and (3) the metal atoms have C2 symmetry and in (1) there is a marked cis distortion of the Cu–O distances. In (2) a distortion of the CuN4O2 chromophore towards a square pyramidal (4 + 1 + 1*) stereochemistry is present. The polycrystalline e.s.r. spectra of (1) and (2) and of 10% copper(II)-doped (3) are temperature variable, consistent with a fluxional CuN4O2 chromophore stereochemistry. The temperature variability of the single-crystal e.s.r. spectra of (1), (2), and copper(II)-doped (3) is restricted to the CuN2O2 plane, consistent with two-dimensional fluxional behaviour. The electronic reflectance spectra of (1) and (2) involve two peaks at ca. 10 000 and ca. 14 000 cm–1 and relate to the underlying static CuN4O2(4 + 1 + 1*) chromophore stereochemistry.

Unidentate versus symmetrically and unsymmetrically bidentate nitrate co-ordination in pyrazole-containing chelates. The crystal and molecular structures of (nitrato-O)[tris(3,5-dimethylpyrazol-1-ylmethyl)amine]copper(II) nitrate, (nitrato-O,O′)[tris(3,5-dimethylpyrazol-1-ylmethyl)amine]nickel(II) nitrate, and (nitrato-O)(nitrato-O,O′)[tris(3,5-dimethylpyrazol-1-ylmethyl)amine]cadmium(II)

The crystal structures of three compounds ML(NO3)2 are described, where M = Cu, Ni, or Cd and L is the tripodal quadridentate ligand tris(3,5-dimethylpyrazol-1-ylmethyl)amine. The structure of the copper compound can best be described as tetragonally distorted trigonal bipyramidal. As in the other compounds, the ligand L utilizes each of its four potential donor sites. One nitrate ion is unidentate, yielding a CuN4O chromophore. In the nickel compound a nitrate ion is symmetrically bidentate, yielding a distorted octahedral cis-NiN4O2 chromophore. In the cadmium compound one of the nitrate ions is unsymmetrically bidentate, the other symmetrically bidentate, yielding a CdN4O3 chromophore. The structure is best described as distorted bicapped octahedral. The nitrate co-ordination modes were investigated using several spectroscopic techniques. Criteria to differentiate between the unidentate, unsymmetrically bidentate, and symmetrically bidentate modes are presented. In this type of compound discrimination between the co-ordination modes solely on the basis of spectroscopic behaviour appears not to be possible. Slight changes in the i.r. spectra of CuL(NO3)2, and of the analogous cobalt and zinc compounds, upon applying pressure can be understood in terms of changes in the nitrate co-ordination.

A comment on the crystal structure and electronic properties of bis(2,9-dimethyl-1,10-phenanthroline)nitratocopper(II) trichloroacetate trichloroacetic acid

A re-examination of the electronic properties and structure of [Cu(dmphen)2(O2NO)][CCl3CO2]·CCl3CO2H (dmphen = 2,9-dimethyl-1,10-phenanthroline) suggests that it is best described as a distorted squarepyramidal cis octahedral CuN4O2 chromophore (4 + 1 + 1*) as suggested by the electronic reflectance spectrum, but involving a novel sense of distortion.

The X-ray crystal structure and electronic properties of [Cu(bipy)2(ONO)][NO3](bipy = 2,2′-bipyridyl) at 298 and 165 K, a fluxional cis-distorted octahedral CuN4O2chromophore

The X-ray crystal structures of [Cu(bipy)2(ONO)][NO3](bipy =2,2′-bipyridyl) are reported at 298 and 165 K; significant differences occur which are consistent with a fluxional behaviour of the CuN4O2 chromophore, and enable the underlying static stereochemistry to be predicted and rationalised using the i.r. spectrum of the nitrito-group and the electronic reflectance spectrum of the CuN4O2 chromophore.

Transition metal chemistry of oxime-containing ligands, part XXIII; some trinuclear copper(II) complexes of quinoline-2-aldoxime and isoquinoline-3-aldoxime

Some copper(II) complexes of types [Cu3(L)3(OH)2](X) and [Cu3(L)3(OH)(SO4)] · 3 H2O (where L=qox, anion of quinoline-2-aldoxime (Hqox) or iqox, anion of isoquinoline-3-aldoxime (Hiqox) and X=Cl, Br, I, NO3, NCS or NCSe) were prepared and characterized by elemental analysis, molecular conductance, magnetic moment (300-77K) and spectral measurements. The complexes are highly antiferromagnetic and have S=1/2. A distorted square-pyramidal structure with CuN2O3 chromophore is proposed.

The crystal structures of [Cu(phen)2(O2CMe)]X (phen = 1,10-phenanthroline) complexes: pseudo cis-distorted octahedral structures and fluxional copper(II) stereochemistries

The X-ray crystal structures of four cation-distortion isomers of the [Cu(Phen)2(O2CMe)]+(phen = 1,10-phenanthroline) cation are reported and shown to contain the cis-octahedral CuN4O2 chromophore; X-ray and e.s.r. data are consistent with a fluxional CuN4O2 structure, which is best described as a psuedo cis-distorted octahedral copper(II) stereochemistry in three of the complexes, and consequently these structural variations can be related to the dynamic pseudo-Jahn-Teller effect.

The single-crystal electronic and electron spin resonance spectra of copper(II) doped bis(2,2′-bipyridyl)nitritozinc(II) nitrate and bis(2,2′-bipyridyl)nitritocopper(II) tetrafluoroborate: a fluxional CuN2N′2O2chromophore

The single-crystal e.s.r. spectra and polarised electronic spectra of the copper(II) doped [Zn(bipy)2(ONO)][NO3] system are shown to be closely comparable to those previously reported for [Cu(bipy)2(ONO)][NO3]. The observation of more than four copper hyperfine lines in the single-crystal e.s.r. spectrum measured in the approximate bc plane is consistent with a two-dimensional misalignment of the CuN2N′2O2 chromophore and the temperature variability of the g and A factors are consistent with a two-dimensional fluxional model of the CuN2N′2O2 chromophore with a distorted square-pyramidal 4 + 1 + 1* structure and not with static disorder. This suggests that the structures of [Cu(bipy)2(ONO)][NO3] and [Cu(bipy)2(ONO)][BF4] are not genuine static stereochemistries of the copper(II) ion, but arise as a consequence of the fluxional model and are best referred to as pseudo cis distorted-octahedral structures. The electronic properties of 0.1–100% copper(II) doped [Zn(bipy)2(ONO)][NO3] are shown to be independent of the copper(II) concentration, and this suggests that the structure of the doped CuN2N′2O2 chromophore is independent of the structure of the ZnN2N′2O2 chromophore of the zinc host lattice, but correlates with the known structure of the [Cu(bipy)2(ONO)][NO3] complex, an example of the Non-co-operative Jahn–Teller Effect. The electronic reflectance spectrum of [Cu(bipy)2(ONO)][BF4] is closely comparable to that of the nitrate, despite having a significantly different, (4 + 1 + 1*) type, fluxional CuN4O2 chromophore structure.

(N-benzoyl-DL-alaninate)copper(II) complexes: effect of amines on the amino-acid co-ordination

Reaction of amines with the complex [Cu(Bz-AlaO)2]·H2O (Bz-AlaO =N-benzoyl-DL-alaninato) gives adducts of the type [Cu(Bz-AlaO)2]·Bn[n= 1,B = piperazine(ppz), 3-methylpyridine(3Me-py), 4Me-py, 2,2′-bipyridine (2,2′-bipy), 4,4′-bipy, and 1.10-phenanthroline (phen); n= 2, B = Meppz, piperidine (pip), morpholine (morp), py, and 4Me-py] and [Cu(en)2(Bz-AlaO)2]. Each complex has been characterized by elemental analysis, solid and solution spectroscopy, and magnetic moment. The complexes may be divided into three types from the point of view of their stereochemistry. Type (1) contains complexes having a copper(II) acetate monohydrate type co-ordination such as [{Cu(Bz-AlaO)2B}2][B = H2O, 3Me-py, 4Me-py, and py (only in solution)], type (2) contains complexes having a square-planar or strongly distorted tetragonal environment with a CuN2O2 chromophore such as [Cu(Bz-AlaO)2]·Bn(B = Meppz, pip, py, 4Me-py, 2,2′-bipy, and 4,4′-bipy) or a CuN4 chromophore such as [Cu(en)2(Bz-AlaO)2](the solution complexes of the Meppz, pip, mor, and 4Me-py adducts, which show a concentration-dependent colour change, are also discussed), and type (3) contains medium tetragonally distorted complexes, as the presence of two d–d bands supports, in the solid [Cu(mor)2(Bz-AlaO)2], solid and solution [Cu(Bz-AlaO)2]·phen, and in the presence of excess of amine, [CuB2(Bz-α-AlaO)2](B = Meppz, pip, mor, 3-Me-py, and 4-Me-py). For the phen adduct a cis-octahedral co-ordination with a CuN2O4 chromophore is proposed. while for the solution complexes in the presence of an excess of amine the CuN4O2 chromophore is suggested.