Themistoclis A. Kabanos

DEPROTONATED AND NON-DEPROTONATED COMPLEXES OF N-(2-AMINOPHENYL) PYRIDINE-2-CARBOXAMIDE AND N-(3-AMINOPHENYL) PYRIDINE-2-CARBOXAMIDE WITH Co(II), Ni(II), Cu(II) AND Pd(II)

Abstract New deprotonated and non-deprotonated chelates of N-(2-aminophenyl)pyridine-2-carboxamide and N-(3-amino phenyl)pyridine-2-carboxamide with Co(II), Ni(II), Cu(II) and Pd(II) have been prepared. Properties, molar conductance measurement, magnetic moment and spectral (IR and visible) data are discussed in terms of possible structural types and the nature of the bonding. The metal ions used promote amide deprotonation on coordination with N-(2-aminophenyl)pyridine-2-carboxamide; only Pd(II) causes the same effect with N-(3-aminophenyl)pyridine-2-carboxamide. The neutral amide group is coordinated to the metal ions through oxygen, while an N(amide)-coordination is assigned for the deprotonated complexes.

The coordination chemistry of N-(2-pyridyl)pyridine-2′-carboxamide; A potentially tridentate ligand containing one secondary amide and two 2-pyridyl donor groups

Abstract New complexes of the general compositions M(LH)X 2 (M = Co, Zn; X = Cl, Br, I), Zn(LH)(NCS) 2 , Zn(LH)(NO 3 ) 2 ·H 2 O, Cu(LH)X 2 (X = Cl, Br, ONO 2 ), Ni(LH)Cl 2 ·H 2 O, Co(LH) 2 X 2 (X = NCS, ONO 2 ), Ni(LH) 2 X 2 (X = Cl, Br, NCS, ONO 2 ), Pt(LH) 2 Cl 2 and MLCl· n H 2 O (M = Ni, Cu, Pd; n = 2, 3), where LH = N -(2-pyridyl)pyridine-2′-carboxamide, have been isolated. The complexes were characterized by elemental analyses, conductivity measurements, X-ray powder patterns, thermal methods, magnetic susceptibilities and spectroscopic (IR, ligand field, 1 H NMR) studies. Pseudotetrahedral, square planar, square pyramidal and distorted octahedral stereochemistries are tentatively assigned in the solid state. Most complexes appear to be monomeric, while polymeric structural types are attributed for Ni(LH)Cl 2 ·H 2 O and CuLCl·2H 2 O. The neutral amide group of LH is coordinated to Co(II), Ni(II), Cu(II) and Zn(II) through oxygen, while N-coordination is observed for PdLCl·2H 2 O. The amide group of L − is bound to different Cu(II) atoms in CuLCl·2H 2 O through both its nitrogen and oxygen. The rare O-coordination of the deprotonated amide bound is proposed for NiLCl· 3H 2 O. The N(1) atom is not involved in coordination except in the complexes Ni(LH)Cl 2 ·H 2 O, NiLCl· 3H 2 O and CuLCl·2H 2 O, where both pyridine residues are coordinated. The variation in structural types observed is believed to be a consequence of the stereochemical adaptability of the ligand to the electronic demands of the metal ions.

The coordination chemistry of N-(2-aminophenyl)- and N-(3-aminophenyl)quinoline-2′-carboxamide; two potentially tridentate ligands containing secondary amide and N-donor groups

Abstract New complexes of the general formulae Co( o -LH) 2 X 2 (XCl, NCS), Co( o -LH) 2 Br 2 ·EtOH (EtOHethanol), M( o -LH)(NO 3 ) 2 (MCo, Ni), Ni( o -LH) 2 X 2 (XCl, Br, NCS), Cu( o -L)X (XCl, Br), Zn( o -LH)X 2 (XCl, Br), Pd( o -L)Cl, Pt( o -LH) 2 Cl 2 ·H 2 O, M( m -LH)Cl 2 · n H 2 O (MCo, Ni, Pd; n =0, 0.5, 1), Cu( m -LH)Cl 2 ·EtOH, M( m -LH) 2 Cl 2 · n H 2 O (MCo, Zn, Pt; n =0, 1), M( m -LH)Br 2 (MCu, Zn), M( m -LH) 2 Br 2 (MCo, Ni), Co( m -LH)(NCS) 2 and Co( m -LH) 2 (NCS) 2 , where o -LH= N -(2-aminophenyl)quinoline-2′-carboxamide and m -LH= N -(3-aminophenyl)quinoline-2′-carboxamide, have been prepared. The complexes were characterised by elemental analyses, conductivity measurements, X-ray powder patterns, thermogravimetric analyses, magnetic moments and spectral ( 1 H NMR, IR, and electronic) studies. Copper(II) and palladium(II) promote amide deprotonation at nearly acidic pH on coordination with o -LH. A variety of stereochemistries is assigned for the complexes prepared. The deprotonated copper(II) and the nickel(II) and palladium(II) complexes of m -LH appear to be polymeric. The neutral amide group of the ligands is coordinated to the metal ions through oxygen, while N(amide)-coordination is observed for the deprotonated complexes. Coordination of the secondary amide group is not observed for Zn( m -LH) 2 Cl 2 , Pd( m -LH)Cl 2 ·0.5H 2 O and platinum(II) complexes. The neutral ligand o -LH shows bidentate N(ring), O-behaviour, while the anion o -L − exhibits tridentate N,N,N-coordination. m -LH acts as a monodentate, bidentate and tridentate ligand depending on the metal ion, the anion and the preparative conditions.

Metal complexes containing the monoanion, dianion and the neutral form of the ligand N-(2-carboxylphenyl)pyridine-2′-carboxamide

New complexes of the formulae M(LH)2·nH2O (M = Co, Ni, Cu, Zn; n = 2, 2.5, 3), Cu2(LH)2L· 3H2O, PdL·H2O, Pt3(LH)4L·7H2O, M2(LH)2(OH)2· nH2O (M = Co, Ni, Zn; n = 2, 4), CuL, M(LH2)2Cl2· EtOH (M = Co, Cu; EtOH = ethanol), Ni(LH2)2Cl2· EtOH·H2O, M(LH2)2X2 (M = Co, Ni; X = NCS, ONO2), Zn(LH2)2(NO3)2, Zn(LH2)(LH)Cl, Cu(LH2)- (LH)NO3 and Cu3(LH)3L(NO3), where LH2=N-(2- carboxylphenyl)pyridine-2′-carboxamide, have been isolated. The complexes were characterised by elemental analyses, conductivity measurements, magnetic moments and spectral (IR, 1H NMR and electronic) studies. Varying stereochemistry is assigned for the complexes prepared in the solid state. The complexes M(LH)2·nH2O (M = Co, Ni, Cu, Zn), Cu2- (LH)2L·3H2O and Cu3(LH)3L(NO3) appear to be polymeric, while dimeric structural types are assigned for M2(LH)2(OH)2·nH2O (M = Co, Ni, Zn) and CuL. Only palladium(II) at acidic pH and copper(II) at basic pH promote amide deprotonation on coordination and yield doubly deprotonated complexes. Coordination of the neutral carboxylic group is not observed for the complexes of LH2; the carboxylate ion exhibits monodentate coordination in the compounds of LH- and L2-. The neutral amide group of the ligands LH2 and LH− is coordinated to the metal ions through oxygen, while N(amide)-coordination is observed for the L2- complexes. The secondary amide bond shows the rare iminol type of coordination in Cu(LH)2·2H2O.

Coordination compounds of N-(2-aminophenyl)- and N-(3-aminophenyl)pyridine-2′-carboxamide with cobalt(II) and cobalt(III). The nature of amide deprotonation induced by cobalt(III) in acidicpH

New complexes of the general formulae CoL2X·nH2O (X=Cl, Br, I, NCS, NO3 andn=0, 1, 2 or 3), Co2L2X3·EtOH (X=Cl, Br, I, NCS), Co(DH)X2 (X=NCS, NO3) and Co(DH)2X2 (X=NCS, I) have been prepared, whereLH=N-(2-aminophenyl)pyridine-2′-carboxamide andDH=N-(3-aminophenyl)pyridine-2′-carboxamide. The compounds were characterized by X-ray powder patterns, conductivity measurements, thermogravimetric analysis, magnetic properties as well as by IR, ligand field and1H-NMR spectroscopy. In the presence of oxygen,LH undergoes a cobalt(III) ion promoted amide hydrogen ionization in thepH region 4–6.ZusammenfassungNeue Komplexe der allgemeinen Formeln CoL2X·nH2O (X=Cl, Br, I, NCS, NO3 undn=0, 1, 2, 3), Co2L2X3·EtOH (X=Cl, Br, I, NCS), Co(DH)X2 (X=NCS, NO3) und Co(DH)2X2 (X=NCS, I) wurden dargestellt mit LH=N-(2-aminophenyl)pyridin-2′-carboxamid undDH=N-(3-aminophenyl)pyridin-2′-carboxamid. Die Verbindungen wurden mittels Röntgenstrukturanalyse, Leitfähigkeitsmessungen, thermogravimetrischen Analysen, magnetischen Eigenschaften sowie mit IR-, Ligandenfeld- und1H-NMR-Spektroskopie charakterisiert. In Gegenwart von Sauerstoff unterliegtLH einer Cobalt(III)ion-induzierten Amidwasserstoffionisierung impH-Bereich 4–6.

Metal complexes of the diuretic drug furosemide

New complexes of the formulaeM(fur)2·2H2O (M = Mn, Cu, Zn),M(fur)2·3H2O (M = Co, Ni, Cd), Hg2(fur)3Cl2·2H2O, Pd(fur)Cl·H2O and Rh(fur)3·3H2O, wherefurH = 4-chloro-N-(2-furfuryl)-5-sulfamoylanthranilic acid, have been prepared and characterized by conductivity measurements, X-ray powder patterns, thermal methods, effective magnetic moments as well as by IR, ligand field,1H-NMR and ESR spectroscopic studies. The anionfur− shows a chelated bidentate O(carboxylato), N(imino)-coordinating behaviour.ZusammenfassungNeue Komplexe der Verbindungen:M(fur)2·2H2O (M = Mn, Cu, Zn),M(fur)2·3H2O (M = Co, Ni, Cd), Hg2(fur)3Cl2·2H2O, Pd(fur)Cl·H2O und Rh(fur)3·3H2O, wobeifurH 4-chlor-N-(2-furfuryl)-5-sulfamoylanthanilsäure ist, wurden dargestellt. Die Komplexe wurden durch Leitfähigkeitsmessungen, Röntgen-Pulver-Aufnahmen, thermogravimetrische Analysen, Messungen des effektiven magnetischen Dipolemomentes sowie durch spektroskopische Untersuchungen (IR,1H-NMR und ESR) charakterisiert. Das Anionfur− zeigt das Verhalten einer Chelat-bidentat-O(carboxylato),N(imino)-Koordination.