Multifunctional Coordination Compounds: Design and Properties (original) (raw)
Related papers
2000
Oxalates containing various 3d transitional elements and positive NH 4 or negative OH groups were newly synthesized. Each above-mentioned component has directly influenced the structure, the electronic or interaction properties, while some unexpected behaviors were revealed by various magnetic and Mössbauer measurements. The main magnetic parameters, the long-range anti-ferromagnetic couplings observed at very low temperature and, particularly the uncompensated moment are discussed in detail. The induced lower spin states for bivalent ions and especially the anti-parallel arrangement of the spins belonging to trivalent and bivalent iron inside the molecule are also emphasized.
Inorganic Chemistry, 2012
A new family of oxalate-bridged chains of formula (C 1)[Mn-(H 2 O) 3 Cr(ox) 3 ]•H 2 O (1), (C 2) 4 [Mn 2 (H 2 O) 3 ClCr 2 (ox) 6 ]Cl•H 2 O•2C 2 H 6 O (2a), (C 2) 4 [Co 2 (H 2 O) 3 ClCr 2 (ox) 6 ]Cl•2H 2 O•2C 2 H 6 O (2b), [Mn(C 3)(H 2 O) 2 Cr-(ox) 3 ]•H 2 O (3), and (C 4) 4 [Mn(H 2 O){Cr(ox) 3 } 2 ]•H 2 O (4) [C 1 + = tetramethylammonium, C 2 + = 4-N,N-dimethylaminopyridinium, C 3 + = 1-hydroxyethyl-4-N,N-dimethylamino-pyridinium, C 4 + = 1-hydroxyethyl-4-(4′-dimethylamino-αstyryl)-pyridinium, ox 2− = oxalate] have been synthesized by self-assembly of the (C n) 3 [Cr(ox) 3 ] (n = 1−4) mononuclear compound and the chloride salts of the corresponding metal(II) ions. The crystal structures of the five chain compounds have been determined by single-crystal X-ray diffraction. Compounds 1 and 2 crystallize in the Pc and P2 1 /c centrosymmetrical space groups, respectively, whereas 3 and 4 crystallize in the C2cb and P1 noncentrosymmetrical space groups, respectively. Compounds 1, 2, and 3 adopt a zigzag chain structure while 4 exhibits a comb-like chain structure consisting of the repetition of the [Mn(H 2 O){Cr(μ-ox)(ox) 2 }{Cr(μ-ox) 2 (ox)}] 4− entities. Compound 3 displays large second-order optical nonlinearity. The magnetic properties of 1−4 have been investigated in the temperature range 2−300 K. Monte Carlo simulations on 1, 2a, 2b, and 3 provide a quantitative description of the magnetic properties indicating ferromagnetic interactions through the bis(bidentate) oxalate bridges [J = +0.55 cm −1 (1), J = +1.02 cm −1 (2a), J = +3.83 cm −1 (2b), and J = +0.75 cm −1 (3) using Hamiltonian Ĥ= −J(Sî•Sĵ)]. On the other side, the fit of the magnetic susceptibility data of 4 by full-matrix diagonalization agrees with a ferromagnetic exchange interaction within the [Mn(H 2 O){Cr(μ-ox)(ox) 2 }{Cr(μ-ox) 2 (ox)}] 4− trinuclear units (J = +2.07 cm −1) antiferromagnetically coupled along the chain. Compound 2b exhibits a metamagnetic behavior, the value of the critical field being H C = 1000 G, due to the occurrence of weak interchain antiferromagnetic interactions.
Dalton Transactions, 2010
We report here two series of [M(II)(ox)(L) 2 ] n coordination polymer chains: the first being [M(II)(ox)(bnz) 2 ] n (M = Mn 1, Fe 2, Co 3, Ni 4, Cu 5 and Zn 6; ox = oxalate C 2 O 4 2− ; bnz = benzimidazole) and the second [M(II)(ox)(btz) 2 ] n (M = Mn 7, Fe 8, Co 9, Ni 10, Cu 11 and Zn 12; btz = benzotriazole). The first series displays an unusual homometallic [−M i −M ii −M ii −] n chain topology and the second series is isostructural to [Fe(II)(ox)(btz) 2 ] n , originally reported by Jia et al. 1 These two series allow us to make comparisons between the spin state of each metal and the magnetic coupling interaction within an isostructural series spanning the full range of spin states available in 3d metals and to investigate which models are the best to use in each case. Additionally, we have synthesised a two-dimensional coordination polymer {[Zn(II)(bnz) 4 ][Zn(II) 2 (ox) 3 ]} n (13), in which distorted hexagonal [Zn(II) 2 (ox) 3 ] n 2n− layers are hydrogen bonded by [Zn(II)(bnz) 4 ] 2+ cations to give an interlayer separation of 12.001(2) Å.
Oxalamide based coordination polymers
Journal of Coordination Chemistry, 2020
Employment of N,N 0-bis(2-dicarboxyphenyl)-oxalamide (H 4 L) in the M 2þ chemistry (M ¼ Mg, Mn, Co, Ni, and Zn) afforded five 2-D coordination polymers and one 1-D coordination polymer. The crystal structures of all complexes have been determined by single-crystal X-ray crystallography. The five 2-D polymers with the general formula [M(H 2 L)(H 2 O) 2 ] n (M ¼ Mg 1, Mn 2, Co 3, Ni 4, Zn 6) are based on the di-anion of the oxalamide ligand (H 2 L 2-) while the poorly diffracting complex 5, f[Ni 2 (L)(H 2 O) 3 ]Á(H 2 O) 2 g n , is based on the tetra-anion of the oxalamide ligand (L 4-). The magnetic properties of 2-4 revealed weak antiferromagnetic interactions between the spin carriers.
Polyhedron, 2013
Four new coordination polymers namely, [Cd 3 (L 1) 2 (DMA) 4 ] n (1), [Mn(HL 1)(H 2 O) 3 ] n (2), [Mn(H 2 L 2)] n (3) and {[Co 2 (HL 2)(L 2)]Á(Et 4 N)Á(1.5H 2 O)} n (4) have been synthesized with semi-rigid ether bridged tricarboxylic acid ligands H 3 L 1 and H 3 L 2 [H 3 L 1 = 5-(4-carboxy-phenoxy)-isophthalic acid and H 3 L 2 = 5-(2-carboxyphenoxy)-isophthalic acid] with various transition metal ions using hydro(solvo)thermal techniques. All the coordination polymers have been structurally characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and X-ray single crystallography. Single crystal X-ray studies show that these coordination polymers contain homometallic clusters varying from dimeric to trimeric units except 2 which is a linear monomeric. On reacting para-isomer of the ligand H 3 L 1 with metal ions, 2D and 3D supramolecular structures have been obtained while with the ortho-isomer H 3 L 2 dimeric 2D and 3D framework were obtained. Topological analysis reveals that 1 and 3 are binodal (3,6)-connected kgd net, 2 is also a binodal (3,3)-connected honeycomb type hcb net, while 4 shows unprecedented (3,3,6)-connected pkb5 topological trinodal-network. Interestingly, 3 and 4 exhibits unusual coordination modes involving one of carbonyl O atom of an acid functional group. Moreover, in 4 ethereal O atom is also coordinated to one of the metal center. All complexes show high thermal stability, thus losing coordinated and lattice solvent molecules in the range, $100-200°C. Upon excitation at 325 nm, compounds 1-4 exhibit solid-state luminescences at room temperature.
Solid State Sciences, 2004
Structural relationships between mixed oxalates with crystal structures consisting of isotypic anionic frameworks [MM (C 2 O 4 ) 4 ] 2− built from dodecahedrally coordinated M and M metals, with counter cations located in tunnels, are described. The principles of a predictive structural derivation, based on the YK(C 2 O 4 ) 2 ·4H 2 O structure type, is presented. Four new phases with isotypic frameworks that conform to the classification and to a proposed empirical six-valence-sum rule are reported. The new oxalates have been synthesised from mild chemistry and their crystal structures have been determined from single-crystal or powder diffraction data. Crystal data for the new phases are: CdZrSr(C 2 O 4 ) 4 ·6H 2 O, S.G. I4m2, a = 11.2362(4) Å, c = 8.6084 Å, Z = 2; InK(C 2 O 4 ) 2 ·4H 2 O, S.G. I 4 1 /a, a = 11.0549(3) Å, c = 8.9735(3) Å, Z = 4; YRb(C 2 O 4 ) 2 ·4H 2 O, S.G. I 4 1 /a, a = 11.4569(3) Å, c = 9.1502(4) Å, Z = 4; Ca 2 Zr(C 2 O 4 ) 4 ·5.5H 2 O, S.G. I4m2, a = 11.2558(2) Å, c = 8.4288(2) Å, Z = 2. The open-framework structures of all phases can be described on the basis of building walls made of mixed dodecahedra MO 8 and M O 8 , connected through bichelating oxalate groups.
Journal of Materials Science, 2007
The hydrothermal syntheses, single-crystal X-ray structures and magnetic properties of [Co(C 4 O 4)(H 2 O) 2 ] (1), [Co 3 (OH) 2 (C 4 O 4) 2 ] Á 3H 2 O (2) and [Fe(OH) 2 (C 4 O 4)] (3) are described. Pale yellow cubes of 1 and brown red crystals of 2 were obtained from the reaction of Co(OH) 2 and squaric acid at 200°C. Brown needle of 3 were obtained similarly from Fe(SO 4) Á 7H 2 O, squaric acid and NaOH. 1 consists of a cubic sodalite arrangement with empty cavities where the Co atoms are connected by l 4-squarate and two trans-water molecules each, while 2 and 3 contain metal-hydroxide double-chains of edge-sharing octahedral, brucite-type for 2 and goethite for 3, connected by l 6-squarate. 2 contains water molecules in the channels which can be removed and re-inserted repeatedly without loss of crystallinity. All three compounds possess 3D frameworks made up of coordination and hydrogen bonds. 1 behaves as a paramagnet while 2 and 3 are antiferromagnets and 2 transforms to a ferromagnet reversibly upon dehydration and rehydration. The structures of two one-dimensional polymers employing 2,5-pyridinedicarboxylate, [Co 2 (H 2 O) 6 (2,5-pydc) 2 ] Á 2H 2 O (4) and Cu (2,5-pydc) 2 (5), are also reported.
Russian Chemical Bulletin, 2007
Clusters with the cuboidal core M 3 M´Q 4 (M = Mo or W; Q = Se or Se; M´ = Ru, Os, Ir, Ni, Pd, Pt, etc.) have attracted interest because of the unusual reactivity of heterometals in the clusters and a great scope for modifi cations of the properties of the clusters by varying the nature of the main metal (Mo or W), the bridging chalco gen atoms, and the ligands coordinated to Mo or W. 1 Nickel and palladium containing clusters of this family exhibit high catalytic activity in the addition reactions of carboxylic acids and alcohols with alkynes, the cycliza tion of acetylenecarboxylic acids into lactones, and the hydrodesulfurization of thiophene derivatives. These clus ters also promote the isomerization of hydrophosphoryl compounds into the corresponding pyramidal tautomers and coordinate π acceptor ligands (CO, alkenes, and alkynes) under mild conditions. 2-8
One-Dimensional Oxalato-Bridged Metal(II) Complexes with 4-Amino-1,2,4-triazole as Apical Ligand
European Journal of Inorganic Chemistry, 2005
Keywords: Chain structures / Oxalato bridging ligand / Triazole / X-ray diffraction / Structure-magnetism relationships The synthesis, chemical characterization, thermal behavior and magnetic properties of six new one-dimensional oxalatobridged metal(II) complexes of formula [M(µ-ox)(4atr) 2 ] n [M II = Cu (1), Ni (2), Co (3), Zn (4), Fe(5)] and [Cd(µ-ox)(4atr) 2 -(H 2 O)] n (6) (ox = oxalato dianion, 4atr = 4-amino-1,2,4-triazole) are reported. The crystal structures of 1 and 6 have been solved by single-crystal X-ray diffraction, whereas the remaining compounds have been studied by means of X-ray powder diffraction methods. Compounds 1-5 are isomorphous and crystallize in the triclinic space group P1 with unit cell parameters for 1 of a = 5.538(1) Å, b = 7.663(1) Å, c = 7.711(2) Å, α = 62.21(1)°, β = 73.91(1)°, γ = 86.11(1)°, and Z = 1. The crystal structures are comprised of one-dimensional linear chains in which the trans-[M(4atr) 2 ] 2+ units are sequentially bridged by bis(bidentate) oxalato ligands, resulting in an octahedral O 4 N 2 donor set. Cryomagnetic susceptibility measurements show the occurrence of antiferromagnetic intrachain interactions for 2, 3, and 5, whereas compound 1 exhibits a weak ferromagnetic coupling in [a] Eur. J. Inorg. Chem. 2005, 4280-4290 R f = Σ|(I obsd. ) 1/2 -(I calcd. ) 1/2 |/Σ(I obsd. ) 1/2 ; R b = Σ|I obsd. -I calcd. |/ΣI obsd. ; R p = Σ|yi obsd. -yi calcd. |/Σyi obsd. ; R wp = [Σwi|yi obsd. -yi calcd. | 2 / Σwi(yi obsd. ) 2 ] 1/2 .