Dinuclear enantiopure Ln complexes with (-) and (-) 2-phenylbutyrate ligands. Luminescence, CPL and magnetic properties.

The reaction of Ln(NO)·6HO (Ln = Nd, Sm, Eu, Tb, Dy, Tm and Yb) with the respective enantiopure ()-(-)-2-phenylbutyric or ()-(+)-2-phenylbutyric acid (/-2-HPhBut) and 4,7-diphenyl-1,10-phenanthroline (Bphen) allows the isolation of chiral dinuclear compounds of the formula [Ln(μ-/-2-PhBut)(/-2PhBut)(Bphen)] where Ln = Nd (R/S-Nd-a), Sm (R/S-Sm-a), Eu (R/S-Eu-a), Tb (R/S-Tb-a and R/S-Tb-b), Dy (R/S-Dy-a and R/S-Dy-b), Tm (R/S-Tm-b) and Yb (R/S-Yb-b). Single crystal X-ray diffraction was performed for compounds S-Eu-a and S-Tm-b. Powder crystal X-ray diffraction was performed for all complexes.

New series of mononuclear β-diketonate cerium(III) field induced single-molecule magnets.

Five new β-diketonate Ce mononuclear complexes, [Ce(Btfa)(HO)] (1), [Ce(Btfa)(phen)] (2), [Ce(Btfa)(bipy)] (3), [Ce(Btfa)(terpy)] (4) and [Ce(Btfa)(bathophen)(DMF)] (5), where Btfa = 4,4,4-trifluoro-1-phenyl-1,3-butanedionate, phen = 1,10-phenanthroline, bipy = 2,2'-bipyridyl, terpy = 2,2':6',2''-terpyridine and bathophen = 4,7-diphenyl-1,10-phenanthroline, have been synthesized and structurally characterized through X-ray diffraction of single crystals. The central Ce atom displays a coordination number of 8 for 1, 2 and 3 and of 9 for 4 and 5. Under a 0 T external magnetic field, none of the given compounds exhibits single molecule magnet (SMM) behaviour.

Luminescence, CPL and magnetic properties of 1D enantiopure Ln complexes with (-) and (-) α-methoxyphenylacetate ligand.

The reaction of Ln(NO)·6HO (Ln = Eu, Tb, Dy and Sm) with ()-(-)-α-methoxyphenylacetic acid (R-HMPA) and 1,10-phenanthroline (phen) in EtOH/HO allows the isolation of 1D chiral compounds of formula [Ln(μ--MPA)(-MPA)(phen)] in which Ln = Eu (R-Eu), Tb (R-Tb), Dy (R-Dy) and Sm (R-Sm). The same synthesis by using ()-(+)-α-methoxyphenylacetic acid (S-HMPA) instead of ()-(-)-α-methoxyphenylacetic acid allows the isolation of the enantiomeric compounds with formula [Ln(μ--MPA)(-MPA)(phen)] where Ln = Eu (S-Eu), Tb (S-Tb), Dy (S-Dy) and Sm (S-Sm). Single crystal X-Ray diffraction measurements were performed for compounds R/S-Eu, R/S-Tb, S-Dy and S-Sm.

Insights into the Spin Dynamics of Mononuclear Cerium(III) Single-Molecule Magnets.

Four novel Ce mononuclear complexes of formulas [Ce(ntfa)(MeOH)] (), [Ce(ntfa)(5,5'-Mebipy)] (), [Ce(ntfa)(terpy)] (), and [Ce(ntfa)(bipy)] (), where ntfa = 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dionato, 5,5'-Mebipy = 5,5'-dimethyl-2,2'-dipyridyl, terpy = 2,2':6',2″-terpyridine, and bipy = 2,2'-bipyridine, have been synthesized and structurally characterized with Ce displaying coordination numbers of 8, 8, 9, and 10, respectively. Magnetic measurements indicate that all the complexes show a field-induced single-ion magnet behavior under a small applied dc field. The magnetic analysis shows the relevance of the different spin relaxation mechanisms in the magnetic relaxation of the Ce compounds, with special emphasis on the local-mode process.

Magnetic and Luminescence Properties of 8-Coordinate Holmium(III) Complexes Containing 4,4,4-Trifluoro-1-Phenyl- and 1-(Naphthalen-2-yl)-1,3-Butanedionates.

A new series of mononuclear Ho complexes derived from the β-diketonate anions: 4,4,4-trifluoro-1-phenyl-1,3-butanedioneate (btfa) and 4,4,4-trifuoro-1-(naphthalen-2-yl)-1,3-butanedionate (ntfa) have been synthesized, [Ho(btfa)(HO)] (), [Ho(ntfa)(MeOH)] (), (), [Ho(btfa)(phen)] (), [Ho(btfa)(bipy)] (), [Ho(btfa)(di-bubipy)] (), [Ho(ntfa)(Mebipy)] (), and [Ho(ntfa)(bipy)] (), where phen is 1,10-phenantroline, bipy is 2,2'-bipyridyl, di-bubipy is 4,4'-di--butyl-2,2'-bipyridyl, and Mebipy is 4,4'-dimethyl-2,2'-bipyridyl. These compounds have been characterized by elemental microanalysis and infrared spectroscopy as well as single-crystal X-ray difraction for -. The central Ho ions in these compounds display coordination number 8.

Chiral dinuclear Ln(iii) complexes derived from S- and R-2-(6-methoxy-2-naphthyl)propionate. Optical and magnetic properties.

The reaction of LnCl3·6H2O with (S)-(+)-2-(6-methoxy-2-naphthyl)propionic acid (S-HL), best known as naproxen, and 1,10-phenanthroline (phen) in EtOH allows the isolation of dinuclear chiral compounds S-1-4 of the formula [Ln2(S-L)6(phen)2]·3DMF·H2O [Ln(iii) = Eu (1), Gd (2), Tb (3) and Dy (4)]. The use of the R-enantiomeric species of the HL ligand led to complexes R-1-4 with the formula [Ln2(R-L)6(phen)2]·3DMF·H2O. Compounds R- andS-1, 3 and 4 show strong sensitized metal-centred luminescence in the visible region.

Circularly polarized luminescence on dinuclear Tb(iii) and Eu(iii) complexes with (S-) and (R-) 2-phenylpropionate.

The reaction of Ln(NO)·6HO (Ln = Tb and Eu) with (S)-(+)-2-phenylpropionic acid (S-HL) and 1,10-phenanthroline (phen) in EtOH/HO allows the isolation of the dinuclear chiral compounds of the formula [Ln(S-L)(phen)]·2.5·S-HL in which Ln = Tb (S-1), Ln = Eu (S-2). The same synthesis by using (R)-(-)-2-phenylpropionic acid (R-HL) instead of (S)-(+)-2-phenylpropionic acid allows the isolation of the enantiomeric compounds with the formula [Ln(R-L)(phen)]·2.

Predetermined Ferromagnetic Coupling via Strict Control of M-O-M Angles.

An imidazolidine-phenolate ligand HL yields quadruple-bridged (μ-NCN)(μ-O) ferromagnetic dinuclear nickel and cobalt complexes. Both kinds of bridges contribute to the ferromagnetic coupling, but the ferromagnetism of these samples is mainly ascribed to the double μ-O links, on the basis of density functional theory calculations. These studies demonstrate not only that the short M-O-M angles of the MO cores favors the parallel alignment of the electrons but also that these angles are the optimal ones for maximizing the ferromagnetic contribution in these complexes.

μ1,1-R-phenylcyanamido bridges as a new safe synthetic strategy for ferromagnetic molecular clusters.

The reaction of Ni(NO3)2·6H2O with di-2-pyridyl ketone, (py)2CO, and the R-phenylcyanamides 4Cl-3CF3-PhHNCN and 4F-3CF3-PhHNCN in CH3OH or CH3CH2OH allows the isolation of the tetranuclear compounds [(Ni4(μ-py2COOCH3)2(μ3-py2COOH)2(μ1,1-4Cl-3CF3-PhNCN)2(4Cl-3CF3-PhNCN)2]·CH3OH (1), [(Ni4(μ-py2COOCH2CH3)2(μ3-py2COOH)2(μ1,1-4Cl-3CF3-PhNCN)2(4Cl-3CF3-PhNCN)2]·2EtOH (2) and [(Ni4(μ-py2COOCH3)2(μ3-py2COOH)2(μ1,1-4F-3CF3-PhNCN)2(4F-3CF3-PhNCN)2]·4CH3OH (3). {(py)2C(OH)O}(-) and {(py)2C(OR)O}(-) are the monoanions of the gem-diol and hemiketal (R = CH3, CH2CH3) forms of (py)2CO. X-ray diffraction analysis reveals defective double-cubane tetrameric entities in which the Ni(II) atoms are linked by μ1,1-R-phenylcyanamido bridges and two kinds of O-bridges.

Different topologies in three manganese-μ-azido 1D compounds: magnetic behavior and DFT-quantum Monte Carlo calculations.

The syntheses and structural characterization of three new monodimensional azido-bridged manganese(ii) complexes with empirical formulae [Mn(N3)2(aminopyz)2]n (1), [Mn(N3)2(4-azpy)2]n (2) and [Mn(N3)2(4-Bzpy)2]n (3) (pyz = pyrazine (1,4-diazine)), 4-azpy = 4-azidopyridine and 4-Bzpy = 4-benzoylpyridine) are reported. 1 is a monodimensional compound with double EO azido bridges, 2 is an alternating monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EE and 3 is a monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EO-diEO-di-EO-di-EE. The magnetic properties of 1-3 are reported.

Four new trinuclear {Cu₃(μ₃-OH)(oximate)₃}²⁺ clusters: crystal structure and magnetic behaviour.

Four new triangular copper(II) complexes with the fragment {Cu3(μ3-OH)(oximate)3}(2+) and formulae [Cu3(μ3-OH)(μ-Cl)(Py2CNO)3((t)BuPO3H)]·4H2O (1), [Cu3(μ3-OH)(μ-Br)(Py2CNO)3((t)BuPO3H)]·3.5H2O (2), [Cu3(μ3-OH)(μ-Br)(PhPyCNO)3((t)BuPO3H)(MeOH)]·1.5 MeOH (3), [Cu3(μ3-OH)Cl2(PhPyCNO)3]·0.

Metal ions directing the geometry and nuclearity of azido-metal(II) complexes derived from bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)amine.

The reaction of a methanolic solution containing M(ClO(4))(2)·nH(2)O (M = Cu, Ni, Zn or Cd) or CoCl(2)·6H(2)O with bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)amine (bedmpza) in the presence of NaN(3) afforded the complexes [Cu(bedmpza)(μ(1,1)-N(3))](2)(ClO(4))(2) (1), [Ni(bedmpza)(N(3))(μ(1,1)-N(3))](2)·1.5H(2)O (2), [Co(bedmpza)(N(3))(2)] (3), [Zn(bedmpza)(N(3))]ClO(4) (4) and [Cd(bedmpza)(N(3))(μ(1,1)-N(3))](2)·1.5H(2)O (5).

Hexanuclear copper(II) cages built on a central {μ3-O···H···μ3-O} moiety, 1,3-bis(dimethylamino)-2-propanolato and capping R-phosphonates: crystal structures, magnetic behavior, and DFT studies.

The syntheses, structural characterization, and magnetic behavior of two new hexanuclear copper(II) complexes derived from R-phosphonic acids and 1,3-bis(dimethylamino)-2-propanol (Hbdmap) with formulas [Cu(6)(μ-bdmap)(3)(μ(3)-Ph-PO(3))(2)(μ(3)-O···H···μ(3)-O)(ClO(4))(2)(H(2)O)]·5H(2)O (1) and [Cu(6)(μ-bdmap)(3)(μ(3)-t-Bu-PO(3))(2)(μ(3)-O···H···μ(3)-O)(μ(1,3)-dca)(dca)(H(2)O)]·6H(2)O (2) (Ph-H(2)PO(3) = phenylphosphonic acid, t-Bu-H(2)PO(3) = tert-butylphosphonic acid, dca = dicyanamide) are reported. Compounds 1 and 2 are hexanuclear 3.111 R-phosphonate(2-)/1,3-bis(dimethylamino)-2-propanolato(1-) cages including in the center the [μ(3)-O···H···μ(3)-O](3-) unit.

Polynuclear copper(II) complexes of di-2-pyridyl ketone derivatives and tert-butylphosphonic acid: crystal structures and magnetic behaviour.

The syntheses, structural characterization, and magnetic behavior of four new copper(II) complexes derived from tert-butylphosphonic acid and di-2-pyridyl ketone with formulae [Cu{(py)(2)C(OH)(2)}](C(4)H(9)PO(3)H)(2).(H(2)O)(2) (1), [Cu(2)(mu(2)-C(4)H(9)PO(3)H){(py)(2)C(OCH(2)CH(3))O}(mu(2)-NO(3))(NO(3))(H(2)O)](n).(H(2)O)(n) (2), [Cu(4)(mu(2)-C(4)H(9)PO(3)H)(2)(mu(4)-C(4)H(9)PO(3))(2){(py)(2)C(OCH(3))O}(2)].

Octanuclear manganese(II,III) clusters stabilized with diamino-alcoxo ligands.

The employment of the 1,3-bis(dimethylamino)-2-propanolate (bdmap) ligand as a chelating/bridging ligand in manganese chemistry is described. The reaction of Mn(R-BzO)(2) and bdmap affords [Mn(8)(O)(4)(R-BzO)(12)(bdmap)(2)(H(2)O)(2)], R = H (1), R = 3-Cl (2) and R = 4-Cl (3), which are mixed-valence Mn(II)(2)Mn(III)(6) clusters. Structural characterization was achieved for 1 and 2, which can be described as a central double defective dicubane Mn(III)(4) subunit, capped by two oxo-bridged Mn(II)-mu(bdmap)-Mn(III) dinuclear units.

Rational design of manganese-micro-azido 3D compounds by using diazines as co-ligands: synthesis, structure and magnetic behaviour.

The syntheses, structural characterization, and magnetic behaviour of three new 3D manganese(II) complexes with the empirical formulae [Mn(N3)2(5-Brpym)]n (1), [Mn(N3)2(Mepyz)]n (2) and [Mn(N3)2(2-acpy)]n (3), (5-Brpym=5-bromopyrimidine, Mepyz=methylpyrazine, 2-acpy=2-acetylpyridine), are reported. In 1, each manganese atom is linked to the four nearest neighbours by only end-to-end azido bridges, forming square layers. These layers are further connected to 3D networks by the N,N'-bridging ligand.

2D copper(II) complex built from N-methyl-1,3-diamino-2-propanolate and azide ligands: structure, magnetic, and DFT studies.

The synthesis, structural characterization, and magnetic behavior of a new 2D copper(II) compound with formula {[Cu2(mu-O2CMe)(mu-MedapO)(mu1,1-N3)2]n (CH3OH)n} 1, in which MedapOH is N-methyl-1,3-diamino-2-propanol is reported herein. 1 crystallizes in the triclinic system, space group P1, with unit cell parameters a = 6.688(5) A, b = 10.

Squarato-metal(II) complexes. 2. unusual bonding mode for a squarato-bridged trinuclear copper(II) complex.

Herein, we report the structural characterization and magnetic properties of the unique squarato-bridged-tricopper(II) complex, [Cu3(pmap)3(micro1,2,3-C4O4)](ClO4)(4).2H 2O (1), based on the tripod tripyridylamine ligand bis[2-(2-pyridyl)ethyl]-(2-pyridyl)methylamine (pmap). Each of the three copper centers is penta-coordinated by four N atoms of a pmap ligand and one bridging O atom of the central squarato dianion.

Ferromagnetic coupling in a 1D coordination polymer containing a symmetric [Cu(mu1,1-N3)2Cu(mu1,1-N3)2Cu]2+ core and based on an organic ligand obtained from the solid state.

Addition of rctt-tetrakis(2-pyridyl)cyclobutane (2,2'-tpcb) in a Cu(II)/N(3)- solution afforded the 1D coordination polymer [Cu(3)(N(3))(6)(2,2'-tpcb)(DMF)(2)](n) (1). The ligand 2,2'-tpcb serves as a tetradentate bis-chelating ligand by linking linear [(DMF)Cu(mu(1,1)-N(3))(2)Cu(N(3))(2)(mu(1,1)-N(3))(2)Cu(DMF)] trinuclear units to produce a zigzag chain. Within each centrosymmetric trinuclear unit there exist two irregularly asymmetric end-on double azido-bridged [Cu(mu(1,1)-N(3))(2)Cu](2+) cores, while one of the largest Cu-Nazide-Cu angles is observed.

1D and 2D end-to-end azide-bridged cobalt(II) complexes: syntheses, crystal structures, and magnetic properties.

Two new polynuclear azido-bridged Co(II) compounds with formulas catena-[Co(mu1,3-N3)(N3)(py)2(H2O)]n (1) and [Co(mu1,3-N3)2(4-acpy)2]n (2) (py=pyridine, 4-acpy=4-acetylpyridine) have been structurally and magnetically characterized. Compound 1 crystallizes in the orthorhombic system Fddd space group and consists of a single end-to-end azido-bridged chain with the Co(II) atoms in a CoN5O slightly distorted octahedron. Compound 2 crystallizes in the monoclinic system P21/a space group and shows 2D sheets built up through end-to-end azido bridges with the Co(II) atoms in a CoN6 environment.

A new 2D network built from potassium sandwiches {K[Cu(II)3(bdap)3]2} and {(micro(1,3)-SCN)3Cu(I)(NCS)} anions: structure and magnetic behaviour.

The addition of a solution of excess K(SCN) to an aqueous solution containing Cu(NO3)2.6H2O and 1,3-bis(amino)-2-propanol (bdapH) yields a novel 2D mixed Cu(I)-Cu(II) complex; X-ray diffraction and magnetic studies are reported herein.

Complementarity and countercomplementarity in polynuclear copper(II) complexes with R2NCH2CH(OH)CH2NR2 (R = H, CH3): crystal structures and magnetic study.

The syntheses, structural characterization and magnetic behavior of five new copper(II) polynuclear compounds with formulae [Cu4(mu2-CH3COO)2(mu-bdmap)2(micro(1,5)-dca)2(dca)2(H2O)2] 1, [Cu2(mu2-CH3COO)(mu-bdap)(mu(1,1,5)-dca)(mu(1,3)-dca)]n 2, [Cu4(mu2-CH3COO)2(mu-bdmap)2(mu(1,1)-NCS)2(NCS)2] 3, [Cu2(mu2-CH3COO)(mu-bdap)(NCS)2] 4 and [Cu2(mu(1,3)-N3)(mu-bdmap)(N3)2]n 5 in which bdmapH is 1,3-bis(dimethylamino)-2-propanol, bdapH is 1,3-bis(amino)-2-propanol and dca is the anionic dicyanamide ligand, are reported herein. Tetranuclear complex 1 crystallizes in the monoclinic system, space group P2(1)/n, with unit cell parameters a = 8.284(8), b = 21.

Five new manganese-mu-azido 2D compounds synthesized in aqueous hydrazoic acid from pyrazine derivatives.

The syntheses, structural characterization, and magnetic behavior of five new 2D manganese(II) complexes with empirical formulas [Mn(N(3))(2)(2,6-DiMepyz)(H(2)O)](n)() (1), [Mn(N(3))(2)(Etpyz)(H(2)O)](n)() (2), [Mn(N(3))(2)(H(2)O)(2)](n)()(2,3-DiMepyz)(n)() (3), [Mn(N(3))(2)(Clpyz)(2)](n)() (4), and [Mn(N(3))(2)(Ipyz)(2)](n)() (5) (pyz = pyrazine (1,4-diazine)) are reported. 1 crystallizes in the monoclinic system, space group P2(1)/c, with unit cell parameters a = 7.513(4) A, b = 17.