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Titolo:
INFLUENCE OF THE BRIDGING GROUP OF CROSS-CONJUGATED NITROGENOUS BASESON THE SPECTRA AND STRUCTURE OF SOLVATOCHROMIC MIXED-LIGAND COPPER(II) CHELATES CONTAINING BETA-KETOENOLS
Autore:
TSIAMIS C; HATZIDIMITRIOU AG; TZAVELLAS LC;
Indirizzi:
UNIV THESSALONIKI,DEPT CHEM GR-54006 THESSALONIKI GREECE
Titolo Testata:
Inorganic chemistry
fascicolo: 12, volume: 37, anno: 1998,
pagine: 2903 - 2909
SICI:
0020-1669(1998)37:12<2903:IOTBGO>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRONIC-PROPERTIES; DI-2-PYRIDYL KETONE; COMPLEXES; COORDINATION; CRYSTAL; ION; STEREOCHEMISTRY; MODES;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
45
Recensione:
Indirizzi per estratti:
Citazione:
C. Tsiamis et al., "INFLUENCE OF THE BRIDGING GROUP OF CROSS-CONJUGATED NITROGENOUS BASESON THE SPECTRA AND STRUCTURE OF SOLVATOCHROMIC MIXED-LIGAND COPPER(II) CHELATES CONTAINING BETA-KETOENOLS", Inorganic chemistry, 37(12), 1998, pp. 2903-2909

Abstract

The concomitant reaction of copper(II) with a heterocyclic nitrogenous cross-conjugated Lewis base (2,2'-dipyridyl ketone, dpk, or 2,2'-dipyridylamine, dpamH) and the anion of a 2-substituted 1,3-dione, beta(-), e.g. X-acac(-) (X = H, Me, Cl, CN, NO2) affords mixed-ligand chelates. The composition and structure of the chelates depend on the group linking the pyridyl rings. Chelation renders the 2,2'-dipyridyl ketonesusceptible to nucleophilic attack by protic molecules. It also depends on the group attached to the beta-dionato moiety since electron attracting substituents facilitate ligation of a water molecule when the 2,2'-dipyridylamine is present. Spectroscopic observations indicated square pyramidal or distorted tetragonal stereochemistries of the ensuing mixed-ligand chelates with the carbonyl oxygens and the pyridyl nitrogens forming the basal plane. Confirmation was acquired by X-ray structure determination of representative chelates. The compound [Cu(NC-acac)dpamH(H2O) OClO3] crystallizes in the Pnma space group with Z = 8 (i.e. four molecules per cell), a = 17.996(1) Angstrom, b = 13.972(1) Angstrom,-c = 7.801(1) Angstrom. The copper atom is 2.401(3) Angstrom from the oxygen of the water molecule and 2.60(2) Angstrom from an oxygen atom of the ClO4- group. The chelate [Cu(NC-acac)dpC(OH)OCH3(OClO3), resulting from the addition of methanol to the carbon atom bridgingthe pyridyl rings, crystallizes in the P2(1)/n space group with a = 10.661(1) Angstrom, b = 14.987(2) Angstrom, c = 13.963(1) Angstrom, beta = 110.57(3)degrees, Z = 4. An oxygen of the ClO4- group is in apicalposition, and it is 2.634(8) Angstrom from the copper atom. The etheric oxygen is distanced 2.615(2) Angstrom from the copper atom, and theO-Cu-O angle of these weak bonds is only 154.4(2)degrees. In these chelates the nitrogenous bases adopt the boat conformation with the pyridyl rings forming dihedral angles of approximately 33 degrees.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/12/20 alle ore 15:58:41