U. Casellato

Platinum(II) and palladium(II) complexes with dithiocarbamates and amines: synthesis, characterization and cell assay

The [M(ESDT)Cl]n (M = Pd or Pt; ESDT = EtO2CCH2(CH3)NCS2, methylamino-acetic acid ethyl ester-dithiocarboxylate) species have been reacted with various amines (py, pyridine; PrNH2, n-propylamine; c-BuNH2, cyclobutylamine; en, ethylenediamine) in dichloromethane or chloroform with the aim to obtain mixed ligand complexes. The neutral complexes [M(ESDT)(L)Cl] (L = py, PrNH2 or c-BuNH2) and the ionic species ([M(ESDT)(L)2]Cl and [M(ESDT)(En)]Cl) have been isolated, and characterized by IR and proton NMR spectroscopies. The crystal structure of [Pd(ESDT)(PrNH2)Cl] has been determined by X-ray crystallography. The behaviour of the complexes in various solvents was described on the basis of the proton NMR spectra. The complexes and the dithiocarbamato intermediates have been tested for in vitro cytostatic activity against human leukemic HL-60 and HeLa cells.

Actinide nitrate complexes

ELT. U. V. W. X. Y. Introduction Modes of coordination of the nitrate group Actinide(II1) nitrates and complexes Actinide(IV) nitrates and complexes (i)Nitrates (ii) Nitrato complexes Actinide(V) nitrates and complexes (i)Nitrates (ii) Nitrato complexes Actinide(V1) nitrates and complexes. (i)Nitratesandnitratehydrates (ii) Nitrato complexes Actinide(IV) nitrate complexes with ligands containing nitrogen donors ..... Actinide(V1) nitrate complexes tiith ligands containing nitrogen donors ..... Actinide(V1) nitrate complexes with ethers Actinide( IV) nitrate complexes with crown ethers Actinide(V1) nitrate complexes with crown ethers Actinide(IV) and actinide(V1) nitrate complexes with cryptates Actinide(IV) nitrate complexes with urea Actinide(V1) nitrate complexes with urea Actinide(V1) nitrate complexes with carbamates Actinide(IV) nitrate complexes with amides Actinide(V1) nitrate complexes with amides Actinide(IV) nitrate complexes with amine N-oxides Actinide(V1) nitrate complexes with amine N-oxides Actinide(IV) nitrate complexes with phosphine and amine oxides _ . _ . _ _ _ . Actinide(V1) nitrate complexes with phosphine and amine oxides ......... Actinide(IV) nitrate complexes with sulphoxides Actinide(VI) nitrate complexes with sulphoxides Conclusions Addendum 184 184 192 193 193 198 202 202 204 204 204 212 216 217 219 219 220 223 224 224 227 229 233 233 234 236 246 251 256 257 258 References . .._ _._____.._ _ _ _._ _ _ _ _.___._____ _ _.._ _ _.__.__._ 259

Lanthanide complexes with compartmental schiff bases

Abstract Lanthanide complexes have been prepared with acyclic and cyclic compartmental Schiff bases (H2L) obtained by condensation of 2,6-diformyl-4-chlorophenol and the polyamines NH2(CH2)2X(CH2)2NH2 (X = NH, S). They can be formulated as Ln(L)NO3· nH2O or Ln(H2L)(NO3)3·nH2O (Ln3+ = La, Nd, Sm, Gd, Tb, Dy, Ho, Er, Yb; n = 0–5) and have been obtained by step-by-step reactions, which allow a more appropriate control of the reaction procedure. Template syntheses often produce not well defined complexes. The Schiff bases act as neutral of dinegative chelating ligands according to the experimental conditions employed. When they coordinate as neutral ligands, one ionic and two bidentate nitrate groups are present in the complexes. A ring contraction, through an interanl cyclization, has been observed in the macrocyclic complexes when X = NH (H2Lc). The crystal structure of [Tb(H2Lc)(NO3)2]NO3 was determined by X-ray crystallography. The compound is monoclinic, space group C2/c, with a = 23.668(5), b = 14.328(7), c = 19.482(5) A and β = 91.82(5)°; Dc = 1.70 g cm−3 for Z = 8. The structure was refined to R = 0.078. The terbium ion is nona-coordinated in the usual coordination geometry of a distorted tricapped trigonal prism. Two nitrato groups are chelate in approximately bisphenoidal position, the third nitrate being ionic. The organic macrocycle is coordinated through two oxygen and three nitrogen atoms. Selected bond distance are: TbO(nitrate) 2.46 A (mean), TbO(ligand) 2.25 A (mean), TbN(ligand) 2.54 A (mean).

Macrocyclic and macroacyclic compartmental Schiff bases: synthesis, characterization, X-ray structure and interaction with metal ions

Acyclic, potentially hexadentate (H4LAH4LD) or decadentate (H6LE) compartmental Schiff bases have been obtained by reaction in methanol of 2,3-dihydroxybenzaldehyde and 1,2-diaminoethane, 1,2-diamino-2-methylpropane, 1,3-diamino-2,2-dimethylpropane, 1,2-diaminobenzene or tris(2-aminoethyl)amine in a 2:1 or 3:1 molecular ratios as appropriate. The reaction of 2,6-diformyl-4-Z-phenol (ZCl−, CH3−) with 1,2-diaminobenzene in methanol produced the partially reduced macrocycles (H2LF and H2LG). Similarly symmetric tetraimine macrocyclic ligands have been synthesized by cyclo-condensation of the same 2,6-diformyl-4-substituted phenols and 1,5-diamino-3- azapentane (H2LH) or 1,4-bis(3-aminopropyl)piperazine (H2LI). A step by step procedure has been employed for the preparation of the asymmetric macrocycle (H2LL). The ligands are yellow or yellow-orange solids and have been characterized by elemental analyses, IR, 1H NMR spectroscopy and electron impact (EI) or fast atom bombardment (FAB) mass spectrometry. The X-ray crystal structures of H4LC and H2LF have also been solved. Crystals of H4LC, grown from CHCl3, are monoclinic, space group P21/c with a=6.767(4), b=14.106(5), c=18.163(5) A, β=91.05(4)° for Z=4. The molecule is composed of two identical dihydroxybenzaldimine moieties connected by the carbon atom C(9). Three hydroxylic oxygens are protonated while the fourth is negatively charged. An intermolecular hydrogen system, involving the hydroxyl groups, gives rise to the formation of polymer chains parallel to c axis. Crystals of H2LF, grown from CHCl3, are monoclinic, space group P21/a with a=22.481(7), b=8.989(5), c=11.911(5) A, β93.28(5)° for Z=4. The molecule shows some unexpected bond lengths and angles. Two nitrogen atoms of each molecule are iminic, the other two aminic in character. A reduction of two CN bonds occurs during the synthetic procedures with the consequent formation of the partially reduced Schiff base. The coordination properties of the acyclic and cyclic ligands towards d and/or f metal ions have been tested, and the results are discussed in detail.

Mononuclear, homo- and heteropolynuclear complexes with acyclic compartmental Schiff bases

Abstract Acyclic compartmental Schiff bases (H4L) have been synthesized by condensation of 2, 3-dihydroxybenzaldehyde with the diamines NH2RNH2 (R- (CH2)2, H4LA; C(CH3)2CH2, H4LB; CH2C(CH3)2CH2, H4LC; C6H4, H4LD). Mononuclear complexes have been obtained by reaction of these hexadentate ligands with the appropriate metal(II) ions (copper(II), nickel(II), uranyl(VI) or lanthanium(III)) or by template procedure. The d metal ions coordinate into the inner N2O2 compartment, while uranyl(VI) or lanthanium(III) occupy the outer O2O2 site of the ligands. Crystals of Ni(H2LC), grown from a methanol/diethyl ether solution are triclinic, space group P 1 with a=11.040(5), b=13.645(5), c=14.877(6) A; α=71.93(4), β=84.62(5), γ=66.56(5)° for Z=2. The two chemically identical molecules of the nickel complex, present in the asymmetric portion of the cell, contain a methanol or a water molecule, respectively, linked by hydrogen bonds in the O2O2 outer site. The coordination around nickel ions, placed in the N2O2 sites, is not strictly planar, all atoms being tetrahedrally displaced from the mean coordination planes by about 0.047 and 0.093 A (mean) for the two molecules A and B, respectively. The metal ion is displaced by 0.026 and 0.015 A from the same planes. The average bond lengths for NiO and NiN are 1.84 A. In the heteropolynuclear complexes MLn(H2L)(X)3, [MLn(L)(NO3)(S)]2 and MUO2(L)(S), (MCu2+, Ni2+; LnLa, Gd; SH2O, MeOH, dmso), obtained by a step by step procedure, the smaller d ion always occupies the inner N2O2 chamber, while the larger f ion occupies the outer O2O2 chamber. The ligands and the complexes have been characterized by IR, 1H and 13C NMR, X-ray, mass spectrometric and magnetic susceptibility studies. The temperature dependence of the magnetic susceptibility of heterodinuclear and heterotetranuclear complexes containing copper(II) and gadolinium(III) ions, in the temperature range 4.2–300 K, shows a ferromagnetic interaction between the d and f metal ions (JCuGd=1.59(3) and -3.76(4) cm-1 for CuGd(H2LA)(NO3)3 and [CuGd(LA)(NO3)(H2O)]2, respectively.

New acyclic and cyclie Schiff bases derived from 2,6-diformyl-4-chlorophenol and their interaction with uranyl(Vl), copper(II) and nickel(Il) ions

Abstract New acyclic and cyclic Schiff base compartmental ligands have been prepared, by reaction of 4-chloro- 2,6-diformylphenol and polyamines of the type NH 2 (CH 2 ) 2 X(CH 2 ) 2 NH 2 (X = NH, S). These ligands have two similar or dissimilar compartments in dose proximity and can link two metal ions in an identical or different coordination mode. The preparation of mono and binuclear uranyl(VI), nickel(II) and copper(II) complexes is also reported together with their physicochemical properties. For the mononuclear species, with ligands having dissimilar compartments, the site occupancy is also discussed on the basis of IR, UV and magnetic properties. For the homobinuclear copper(II) and nickel(II) complexes an antiferromagnetic interaction between the two paramagnetic centres is suggested.

The preparation and characterisation of metal complexes of a new binucleating ligand having two different coordination sites

Abstract A new ligand, referred to as H 4 aapen, has been prepared; it is the ethylenediamine Schiff base derivative of o -acetoacetylphenol and has one site with two nitrogen and two oxygen atoms (N 2 O 2 ) and a second site with four oxygen atoms (O 2 O 2 ) two central oxygens being common to both sites. A series of mono-nuclear complexes have been prepared from this ligand in order to investigate the coordination selectivity of the two compartments. In Ni(H 2 aapen) the nickel(II) is in the N 2 O 2 site, while in UO 2 (H 2 aapen)(H 2 O) and Li 2 [UO 2 (aapen)(H 2 O)]H 2 O the uranyl ions are in the O 2 O 2 site. Positional isomers can be prepared with copper(II): one having the copper in the O 2 O 2 site and the other with copper in the N 2 O 2 one. The mononuclear complexes were used as ligands to prepare the binuclear complexes MM′(aapen) (M = Ni 2+ , Cu 2+ , UO 2+ 2 ; M′ = Ni 2+ , Cu 2+ ). These complexes were characterized on the basis of the analytical data, mass, ir, uv spectra and magnetic moments at room temperature.

Reactivity of the [ReNR]3+ and [ReN]2+ cores toward bis(diphenylphosphino)amine and its derivatives. Synthesis and crystal structures

The complexes fac-[Re(NMe)Cl3{NH(PPh2)2-P,P′}]1, [ReNCl{NH(PPh2)2-P,P′}2]X (X = Cl 2 or BPh42a), [Re(NMe) Cl2{N(XPPh2)2-X,X′}(PPh3)](X = 0 3, S 4 or Se 8), [Re(NMe)Cl{N(XPPh2)2-X,X′}2](X = S 5 or Se 9), [ReNCl{N(SPPh2)2-S,S′}(PPh3)]6, [ReN{N(XPPh2)2-X,X′)2](X = S 7 or Se 10) and trans-[ReOCl2{N(OPPh2)2-O,O′}(AsPh3)]11 were obtained by treatment of [Re(NMe)Cl3(PPh3)2], [ReNCl2(PPh3)2] or [ReOCl3(AsPh3)2] with the appropriate ligand under different experimental conditions. The structures of complexes 1, 2a and 6 were determined by X-ray crystallography. In 1 and 2a the Re atom is six-co-ordinate in a distorted octahedral configuration, whereas in 6 the Re atom is five-co-ordinate square pyramidal with the N atom in the apical position.

Asymmetric compartmental macrocyclic ligands and related mononuclear and hetero-dinuclear complexes with d- and/or f-metal ions

[1+1] Asymmetric compartmental macrocycles H 2 L (H 2 L A –H 2 L G ), containing one N 2 O 2 , N 3 O 2 or N 2 O 2 O 2 Schiff base and one adjacent O 2 O 3 , O 2 O 4 or O 2 O 5 ‘crown like’ coordination chamber, have been prepared by self-condensation or by reaction of the appropriate diformyl (H 2 L I –H 2 L III ) and amine precursors in the presence of barium(II) salts, followed by a demetallation reaction of the resulting complexes, Ba(H 2 L)(ClO 4 ) 2 , with guanidinium sulphate. They have been characterised by IR, NMR and mass spectrometry. The single crystal X-ray structural determination of H 2 L C confirms their [1+1] cyclic nature. The mononuclear complexes Ln(H 2 L)(X) 3 · n S (Ln=La-Lu; X=Cl − , NO 3 − ) and Ni(L)· n S have been prepared by reaction of the preformed ligands with the appropriate metal salt, by template procedure or by condensation of the acyclic complexes with the diformyl derivatives Ln(H 2 L′)(X) 3 or Ni(L′) with the appropriate amine. They have been characterised by IR, NMR, magnetic susceptibility and mass spectrometry. In these mononuclear complexes the 4f and transition metal ion invariantly occupy respectively, the crown-like and the Schiff base chamber. In [La(H 2 L C )(H 2 O) 4 ]Cl 3 the single crystal X-ray structure reveals that a bicapped square antiprismatic decacoordination about the central metal ion is reached by the coordination of the oxygen atoms of the crown-ether chamber and by the oxygen atoms of four water molecules. A Schiff base occupancy has been obtained by the lanthanum ion only when Ba(H 2 L)(ClO 4 ) 2 was used instead of the free ligand H 2 L: the barium ion remains in the crown-ether chamber and obliges the incoming lanthanum ion to fill the Schiff base site. By this procedure the hetero-dinuclear complex, LaBa(L D )(ClO 4 ) 2 (OH)·3H 2 O, has been obtained. La(H 2 L C )(Cl) 3 , by reaction with the appropriate metal salt, gives rise to the hetero-dinuclear species MLa(L C )(Cl) 2 (OH)· n H 2 O (M=Cu, n =1; M=Ni, n =2). LaNa(L D )(X) 2 ·(X=Cl, NO 3 ) and LaNa(L F )(NO 3 ) 2 have been synthesised by template procedure or by reaction of H 2 L D or H 2 L F with the appropriate lanthanum(III) salt and sodium hydroxide.

Preparation, properties and coordination behaviour of planar or tridimensional compartmental Schiff bases

Abstract Planar compartmental Schiff bases containing an inner N2O2 or N3O2 and an outer O2O2 chamber were prepared by condensation of 3-methoxysalicylaldehyde with 1, 2-diaminoethane (H2LA) or 4-N-dodecyldiethylenetriamine (H2LB). Mononuclear and homodinuclear complexes were synthesized by reaction of the ligands with metal salts or by template procedure; heterodinuclear complexes were obtained by step by step reactions. Tridimensional compartmental ligands, containing an inner N4O3 and an outer O3O3 chamber, obtained by condensation of tris(2-ethylamine)amine with 3-methoxy-(H3LC) or 3-hydroxysalicylaldehyde (H6LD) form with M(CH3COO)2·nH2O (M  Mn2+, Fe2+) the mononuclear iron(III) and manganese(III) complexes, M(LC) or M(H3LD). In these complexes the oxidation of the central metal ion occurs as ascertained by Mossbauer and X-ray structural determinations. The crystal molecular structure of the manganese(III) complex, MnLC was established by X-ray diffraction methods. This complex crystallizes in the monoclinic system, space group P21/c in a cell of dimensions a = 10.910(4), b = 12.382(4), c = 21.196(6) A and β = 90.91(6)°, with Z = 4. The structure was refined to the conventional agreement index R = 0.057 with 1880 observed reflections. The manganese(III) ion coordinates in the inner chamber, giving rise to an octahedral complex with the N3O3 donor set formed by the phenolate oxygen and the imine nitrogen donor atoms. The apical amine nitrogen is not involved in the coordination. Bond lengths in the octahedral coordination polyhedron are comprised between 1.897(5) and 2.081(6) A for the three oxygens and 2.075(7) and 2.317(7) A for the three nitrogen donors to the metal ion. The possibility of using this manganese(III) complex (MnLC) as a ligand towards Ln(X)3 or KBr has also been studied.