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Complexes [Gd2(piv)6(bath)2]⋅2EtOH (1a⋅2EtOH), [Gd2(piv)6(bath)2]⋅1.5EtOH⋅0.5H2O (1b⋅1.5EtOH⋅0.5H2O), and [Gd2(piv)6(bath)2]⋅H2O (1c⋅H2O), where piv is (CH3)3CCO2− and bath is 4,7‐diphenyl‐1,10‐phenanthroline, which have different molecular and crystal structures, were synthesized and studied by X‐ray diffraction. A unique feature of polymorphs 1a, 1b, and 1c is that they exhibit first‐order phase transitions, namely, structural phase transitions, or melting before thermal decomposition. Magneto‐structural data for binuclear gadolinium pivalates with bath (1), bpy (2), phen (3), and Hpiv (4) ligands and the polymeric complex [Gd(piv)3]n (5) are presented. The complexes were characterized by ESR spectroscopy. The energies of the excited singlet S1 and triplet T1 states of the bath ligand in carboxylates 1a⋅2EtOH, 1b⋅1.5EtOH⋅0.5H2O, and 1c⋅H2O were determined. [ABSTRACT FROM AUTHOR]

The reaction of VOSO4 with K2cbdc (cbdc2– is cyclobutane‐1,1‐dicarboxylate anion) and Ln(NO3)3 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm, Yb, Lu) yielded 17 novel heterometallic LnIII‐VIV compounds comprising stable bis‐chelate units {VIVO(cbdc)2(H2O)}. Three structural types of compounds are formed depending on the nature of the rare‐earth metal: 1D polymers {[Ln(VO)(cbdc)2(H2O)7]·0.5[VO(cbdc)2]}n (structural type I) [Ln = La (1), Ce (2)], 3D polymers {[KLn(VO)2(cbdc)4(H2O)9]·3.5H2O}n (structural type II) [Ln = La (3), Ce (4), Pr (5), Nd (6), Sm (7), Eu (8), Gd (9), Tb (10), Dy (11), Ho (12)] comprising trinuclear units {LnV2}, and octanuclear complexes {[KLn(VO)2(cbdc)4(H2O)11]·2H2O}2 (structural type III) [Ln = Y (13), Er (14), Tm (15), Yb (16), Lu (17)] containing dinuclear units {LnV}. Magnetic properties were investigated for all isolated compounds. The GdIII‐VIV compound has ferromagnetic and antiferromagnetic exchange interactions between isotropic VIV and GdIII ions. Calculations using the DFT method at the UB3LYP/6‐31G(d,p)/SDD level of theory were performed in order to explain the different nature of exchange interactions in two GdIII‐VIV pairs. The YbIII‐VIV complex displays single‐molecule magnet properties; the effective energy barrier was estimated at ΔEeff/kB = 26 K. The magnetic properties of LnIII‐VIV compounds with heavy lanthanide ions (LnIII = Er, Tm, Yb) were rationalized in terms of crystal‐field calculations for LnIII ions. Three structural types of heterometallic LnIII‐VIV substituted malonates were synthesized from the bis‐malonate vanadyl unit and were characterized by single‐crystal and powder XRD and by magnetic measurements. The structures of the new compounds depend on the nature of the rare‐earth metal: a decrease in the LnIII ionic radius is accompanied by a decrease in the nuclearity of the {LnIII‐VIV} unit. [ABSTRACT FROM AUTHOR]

Mononuclear {Cu(Me2mal)2}2- dianion has been used as a building block for the synthesis of six new coordination polymers: {Li2(H2O)2(µ-H2O)[Cu(µ4-Me2mal)(µ-Me2mal)]} n ( 1), {Na2(µ-EtOH)2[Cu(µ5-Me2mal)2]} n ( 2), {K8(µ-H2O)6[Cu(µ-H2O)(µ3-Me2mal)(µ6-Me2mal)]2[Cu2(µ5-Me2mal)4]} n ( 3), {K2M(H2O)5(µ-H2O)3[Cu(µ-Me2mal)(µ3-Me2mal)][Cu(µ-H2O)(µ-Me2mal)(µ3-Me2mal)]} n (M = MgII ( 4) or NiII ( 5); isostructural compounds), and {K4Co3(H2O)8(µ-H2O)4(µ3-OH)2[Cu(H2O)(µ-Me2mal)(µ3-Me2mal)]2[Cu(µ-H2O)(µ3-Me2mal)2]2} n ( 6). It was shown that the structures of the compounds depend on the nature and ionic radius of the heterometal. In particular, the dimensionality of the complexes increases from 1D to 2D and 3D with increasing radius of the s-metal in compounds 1, 2, and 3, respectively. Partial replacement of K+ in 3 by Mg2+, Ni2+, or Co2+ leads to the formation of heterometallic coordination polymers 4 and 5, with 2D structure, and 3D complex 6. The compounds were characterized by single-crystal X-ray diffraction and EPR spectroscopy, and the magnetic properties of compounds 1, 2, and 4- 6 were also studied. Further, the topological analysis of the structures and another 794 known mal-derivatives complexes from Cambridge Structural Database (CSD, version 5.36) was performed. The main regularities determining the coordination modes of ligands and metal cations in relation to structure topology have been established and are discussed. [ABSTRACT FROM AUTHOR]

The reactions of CuSO4 ·5H2O and Ba(R2mal) [R2mal2- is the dianion of 1,1-cyclopropanedicarboxylic acid (H2Cpdc), 1,1-cyclobutanedicarboxylic acid (H2Cbdc), or butylmalonic (H2Bumal) acid] in water give crystals of the 3D coordination polymers [BaCu(Cpdc)2] n ( 1), [BaCu(Cbdc)2(H2O)] n ( 2) and [Ba3Cu3(Bumal)6(H2O)11] n ·2 n(H2O) ( 3). The heating of 2 in air to 200 °C for 60 min results in the removal of the coordinated water molecules to give anhydrous [BaCu(Cbdc)2] n ( 4). The structures of 1- 3 were determined by single-crystal XRD, and that of 4 was derived from powder XRD (XPRD) data. It was assumed that the crystal structures of the polymer complexes that we isolated were determined, to a considerable extent, by the nature of the substituent of the dicarboxylic acid. For 2, the dicarboxylic acid contains closed cyclic moieties, which are retained during dehydration to give 4. A comparative study of the thermal decomposition processes and thermal kinetics of 1- 3 showed that the dehydration proceeds by a single scheme, and the bonds between the structural moieties in the anhydrous intermediates become stronger. The thermal destruction of the anhydrous compounds 1, 4 and { 3} [the dehydrated intermediate of the thermal decomposition of 3, as proved by thermogravimetric analysis (TGA) data] occurs above 170 °C. The phase compositions of their solid products are determined by the thermolysis conditions, and the formation of BaCuO2 from 3 can be realized under milder conditions than those for the formation from 1 and 2. [ABSTRACT FROM AUTHOR]