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Stuart R Batten

Publications and source records attributed to Stuart R Batten.

15 recordsLinked to original sources
PubMed2006

First metal azide complex with isonicotinate as a bridging ligand showing new net topology: hydrothermal synthesis, structure, and magnetic properties.

A new 3D azido-bridged coordination polymer, [Co1.5(N3)(OH)(Isonic)]n (1), has been synthesized and characterized and its magnetic properties studied. Isonicotinate acts as a bridging coligand in this complex. In 1, all of the ligands take tridentate bridging coordination modes, and the overall structure of 1 exhibits a new 3,6-connected net topology.

Azides↗
PubMed2005

Direction of topological isomers of silver(I) coordination polymers induced by solvent, and selective anion-exchange of a class of PtS-type host frameworks.

The construction of two types of coordination polymers with closely related 4-connected topologies [PtS and lvt (4(2).8(4))] were achieved based on a well-designed bent dipyrazine linker, and the topological differences only result from the stereochemistry of silver(I) coordination sphere with the same coordination donors. Selective anion-exchange functions of the series of PtS-type coordination networks containing different counter anions (from small BF4- to very large SbF6-) were identified.

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PubMed2005

A unique cyanide-bridged three-dimensional (3-D) copper(II)-copper(I) mixed-valence polymer containing 1-D water tapes with cyclic pentamer units.

A unique cyano-bridged copper(II)-copper(I) mixed-valence polymer, {[Cu(3)(CN)(4)(H(2)O)(3)](H(2)O)(2)}(n) (1), has been prepared and structurally determined by X-ray diffraction. The cyanide anions with (mu(2),eta(2)) and (mu(3),eta(2)) bridging modes connect the copper centers into a complicated zeolite-like 3-D network. Of further interest, coordinated and lattice water molecules in this structure form 1-D hydrogen-bonded water tapes consisting of linked cyclic pentamer clusters.

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PubMed2005

New bis-, tris- and tetrakis(pyrazolyl)borate ligands with 3-pyridyl and 4-pyridyl substituents: synthesis and coordination chemistry.

The new ligands dihydrobis[3-(4-pyridyl)pyrazol-1-yl]borate [Bp(4py)]-, hydrotris[3-(4-pyridyl)pyrazol-1-yl]borate [Tp(4py)]-, tetrakis[3-(4-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]-, dihydrobis[3-(3-pyridyl)pyrazol-1-yl]borate [Bp(3py)]-, hydrotris[3-(3-pyridyl)pyrazol-1-yl]borate [Tp(3py)]- and tetrakis[3-(3-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]- are derivatives of the well known bis-, tris- and tetrakis-(pyrazolyl)borate cores, bearing 4-pyridyl or 3-pyridyl substituents attached to the pyrazolyl C3 positions. These pyridyl groups cannot chelate to the metal ions in the poly(pyrazolyl) cavity but are externally directed. Structural studies on a range of metal complexes show how, in many cases, coordination of these pendant pyridyl groups to the M(pyrazolyl)n core of an adjacent metal complex fragment results in formation of coordination oligomers or polymeric networks. [Tl(Bp(3py))], [Tl(Bp(4py))] and [Tl(Tp(4py))] form one-dimensional polymeric chains via coordination of one of their pendant pyridyl units to the Tl(I) centre of an adjacent complex fragment; in contrast, in [Tl(Tp(3py))] coordination of all three pendant pyridyl units to separate Tl(I) neighbours results in formation of a two-dimensional polymeric sheet. In [Tl(Tkp(3py))] and [Tl(Tkp(4py))] the Tl(I) is coordinated by two or three of the four pyrazolyl arms, respectively; bridging interactions of pendant 4-pyridyl groups with adjacent Tl(I) centres result in a two-dimensional sheet forming in each case. In Ag(Tkp(4py)) each Ag(I) ion is coordinated by two pyrazolyl rings, and two bridging pyridyl ligands from other complex units, resulting in a one-dimensional chain consisting of pairs of cross-linked zigzag chains. In contrast to these polymeric coordination networks, the structures of [Cu(Tp(4py))] and [(Tp(3py))Cd(CH3CO2)] are dimers, with a pendant pyridyl residue from the first metal centre attaching to a vacant coordination site on the second, and vice versa; these dimers are stabilised by pi-stacking interactions between sections of the two ligands. [Ni(Tp(3py))2] is monomeric, with an octahedral coordination geometry arising from two tris(pyrazolyl)borate chelates; the array of pendant 3-pyridyl groups is involved only in intramolecular hydrogen-bonding. [(Tp(4py))Re(CO)3] is also monomeric, with a facial arrangement of three pyrazolyl ligands and three carbonyls, with the pendant 4-pyridyl groups not further coordinated. [(Tp(2py))Re(CO)3], based on the related ligand hydrotris[3-(2-pyridyl)pyrazol-1-yl]borate, has a similar fac-(CO)3(pyrazolyl)3 coordination geometry.

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PubMed2004

Hybrid materials containing organometallic cations and 3-D anionic metal dicyanamide networks of type [Cp*2M][M'(dca)3].

A new series of hybrid materials of type [Cp*2M][M'(dca)3] has been prepared by cation templation and structurally characterised (M = Fe(III), Co(III); M'= Mn(II), Fe(II), Co(II), Ni(II), Cd(II); dca-= N(CN)2-). The crystallographic analysis of [Cp*2Fe][Cd(dca)(3)] showed that the [Cd(dca)3]- anionic framework is of a symmetrical 3-D alpha-polonium type, containing octahedral Cd nodes and micro (1,5)-dca bridging ligands. The [Cp*2Fe]+ cations occupy the cube-like cavities within the framework. The cationic and anionic-framework sublattices remain magnetically independent and display susceptibilities, over the range 300 to 2 K, of a Curie-Weiss nature obtained by adding a S= 1/2 (Cp*2Fe+) or a S= 0 (Cp*2Co+) contribution to those of the weakly antiferromagnetically coupled frameworks of M'. These hybrid species do not show any intrinsic long-range magnetic order. The present [Cp*2Fe]M'(dca)3] series display the characteristic, unusually shaped [Cp*2Fe]+ Mossbauer line, in the range 295-5 K, assigned (below 101 K) as the sum of a narrow and a broad line. Relaxation effects were evident. The [Fe(dca)3]- compound showed superimposed low-spin Fe(III) and high-spin Fe(II) lines, the latter giving relaxation broadening effects.

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PubMed2004

Designing dinuclear iron(II) spin crossover complexes. Structure and magnetism of dinitrile-, dicyanamido-, tricyanomethanide-, bipyrimidine- and tetrazine-bridged compounds.

In order to expand the few known examples of dinuclear iron(II) compounds displaying (weak) intradinuclear exchange coupling and spin-crossover on one or both of the iron(II) centres, various dinuclear compounds have been synthesised and assessed for their spin-crossover and exchange coupling behaviour. The key aim of the work was to prepare and structurally characterise 'weakly linked' and 'covalently bridged' systems incorporating bridging ligands such as alkyldinitriles (e.g.NC(CH(2))(4)CN), bipyrimidine (bpym), dicyanamide (dca(-)), tricyanomethanide (tcm(-)), 3,6-bis(2-pyridyl)tetrazine (bptz) and 3,6-bis(2-pyridyl)2,5-dihydrotetrazine (H(2)bptz). The 'end groups', which complete the Fe(ii)N(6) chromophores, include tris(2-pyridylmethyl)amine (tpa), di(2-pyridylethyl)(2-pyridylmethyl)amine (tpa'), 3-(2-pyridyl)pyrazole (pypzH), 1,10-phenanthroline (1,10-phen), tris(pyrazolyl)methane (tpm) and NCX(-)(X = S, Se). It was quite difficult to achieve the spin-crossover condition, many ligand combinations yielding high-spin/high-spin (HS-HS) Fe(II)Fe(II) spin states at all temperatures (300-2 K) with very weak antiferromagnetic coupling (J < -1 cm(-1)), two such being the crystallographically characterised [(dca)(tpm)Fe(mu(1,5)-dca)(2)Fe(tpm)(dca)], 5, and [(tpa')Fe(mu(1,5)-tcm)(2)Fe(tpa')](tcm)(2)(H(2)O)(2), 6. In contrast, a strong field was created around the Fe(II) centres in [(tpa)Fe(mu-(NC(CH(2))(4)CN))(2)Fe(tpa)](ClO(4))(4).NC(CH(2))(4)CN, 1, and the Fe-N bond distances, at 173 K, reflected this. This weakly-linked dinitrile example showed a spin-crossover beginning above 300 K. 'Half crossover' examples, yielding HS-LS states below the spin transition, similar to those noted by Real and coworkers in some mu-bpym systems, were noted for [(1,10-phen)(NCS)(2)Fe(mu-bpym)Fe(NCS)(2)(1,10-phen)], 2, [(pypzH)(NCSe)(2)Fe(mu-bpym)Fe(NCSe)(2)(pypzH)], 4, and [(tpa)Fe(mu-H(2)bptz)Fe(tpa)](ClO(4))(4), 8. Interestingly, the mu-bptz analogue, 7, remained LS-LS at all temperatures with the start of a broad spin crossover evident above 300 K. No thermal hysteresis was evident in the spin transitions of these new dinuclear crossover species indicating a lack of intra- or interdinuclear cooperativity.

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PubMed2004

Synthesis, structure and magnetism of new single molecule magnets composed of MnII2MnIII2 alkoxo-carboxylate bridged clusters capped by triethanolamine ligands.

A family of tetranuclear mixed-valent Mn(II)(2)/Mn(III)(2) complexes of type [Mn(4)(LH(2))(2)(LH)(2)(H(2)O)(x)(RCO(2))(2)](Y)2.nS has been synthesised and structurally characterised, where LH(3) = triethanolamine (N(CH(2)CH(2)OH)(3)), (R=CH(3), x=2, Y = CH(3)CO(2)-, n=2, S = H(2)O; 1), (R=C(6)H(5), x=0, Y=C(6)H(5)CO(2)-, n=1, S = CH(3)CN; 2), (R=C(2)H(5), x=0, Y=ClO(4)(-), n=0; 3). A common structural core was deduced from X-ray crystallography and consists of a rhomboidal (planar-diamond) array with two 7-coordinate Mn(II) "wingtip (w)" centres and two 6-coordinate Mn(III) "body (b)" centres. The Mn(III) ions are bridged to the Mn(II) ions by mu3-oxygen atoms from a deprotonated alcohol "arm" of each tridentate LH(2-) ligand and by mu2-oxygen atoms from each tetradentate LH(2)(-) ligand. The four nitrogen atoms from LH(2-) and LH(2)(-) groups, together with bridging and terminal carboxylates oxygens complete the outer coordination sites around the Mn atoms. A feature of these clusters is that they are linked together in the crystal lattice by hydrogen-bonding interactions involving a non-coordinated hydroxyl arm on each LH(2-) group. Detailed DC and AC magnetic susceptibility measurements and magnetisation isotherms have been made on the three complexes and show that intra-cluster ferromagnetic coupling is occurring between the S = 2 Mn(III) and S = 5/2 Mn(II) ions to yield S = 9 ground states. The g, J(bb) and J(wb) parameters have been deduced. Inter-cluster antiferromagnetic coupling was noted in and this influences the magnetisation versus field behaviour and the temperature and magnitude of the out-of-phase AC chi"M maxima in comparison to those observed for and. An Arrhenius plot of the reciprocal temperature of the maxima in chi"M obtained at different frequencies (10 to 1500 Hz), in the range 1.75 K to 4 K, against the natural logarithm of the magnetization relaxation rate (1/tau) yielded values of the activation energies and pre-exponential factors for two of these new tetranuclear single-molecule magnets (SMMs), and. The activation energies were compared with the potential energy barrier height, U, for magnetisation direction reversal (U = DS(2)) using the axial zero-field splitting parameter, D, deduced from the DC M/H isotherm analysis for these S = 9 species. The very small separation of S = 9 and 8 levels for these clusters highlights the limitations in the determination of D values from M/H data at low temperatures.

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PubMed2004

Preparation of acentric porous coordination frameworks from an interpenetrated diamondoid array through anion-exchange procedures: crystal structures and properties.

The formation, crystal structures, and properties of a series of three-dimensional (3-D) Cu(II) coordination polymers, [[Cu(L)2(H2O)2](PF6)2(H2O)(1.25)]n (1), [[CuL(N3)2](H2O)(1.5)]n (2), and [[CuL(H2O)(SO4)](H2O)2]n (3), with an angular bridging ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L) are reported. Complex 1 crystallizes in the tetragonal I4(1)/a space group (a = b = 13.462(2) A, c = 46.47(1) A, Z = 8), complex 2 in the orthorhombic Pna2(1) space group (a = 6.379(2) A, b = 10.060(3) A, c = 27.232(9) A, Z = 4), and complex 3 in the orthorhombic P2(1)2(1)2(1) space group (a = 5.510(2) A, b = 10.576(4) A, c = 28.34(1) A, Z = 4). Different polymeric frameworks are obtained by only varying the counterions. These include the 2-fold interpenetrated diamondoid structure of 1, the acentric alpha-Po network of 2, and the chiral open framework of 3 with (6(3)).(6(9).8) topology. The interesting anion-exchange, porous, and magnetic properties of these coordination supramolecules have been investigated in detail.

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PubMed2003

A new self-penetrating uniform net, (8,4) (or 8(6)), containing planar four-coordinate nodes.

Hydrothermal reaction of 3-(3-pyridyl)acrylic acid (pyaraH) with NiCl2 and NaOH results in formation of different polymorphs at different temperatures. alpha-Ni(pyara)2(H2O)2 forms at 180 degrees C, and has a 3D polymeric structure. The topology of the network is that of a self-penetrating, four-coordinate (8,4) network (Schläfli symbol 86). This is the first uniform net to contain only planar four-coordinate nodes, and it is also the first four-coordinate uniform net not to have the Schläfli symbol 66. Tauhis fundamental network topology has been previously unrecognized. Tauhe second polymorph, the beta phase, forms from an analogous reaction at 150 degrees C, and contains 1D chains hydrogen bonded into a 3D network.

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PubMed2003

AgC(CN)3-based coordination polymers.

Reaction of Ag(tcm), tcm = tricyanomethanide, C(CN)(3)(-), with a range of terminal and bridging ligands results in formation of a series of new coordination polymers. Recrystallization of Ag(tcm) from acetonitrile generates Ag(tcm)(MeCN), which is composed of corrugated (6,3) sheets displaying two-fold 2D --> 2D parallel interpenetration and is topologically identical to the parent Ag(tcm) structure. Ag(tcm)(L) species, L = 1,4-diazobicyclo-[2.2.2]-octane (dabco) or 4,4'-bipyridine (bipy), contain two interpenetrating 3D networks composed of 3-connecting (tcm) and 5-connecting (Ag) centers. The structure of Ag(tcm)(bpe), bpe = 1,2-bis(4-pyridyl)ethene, contains 1D ladderlike polymers connected by weak Ag-tcm interactions into two interpenetrating 3D nets. Ag(tcm)(Mepyz)(3/2), Mepyz = methylpyrazine, also contains 1D ladders, while Ag(tcm)(Me(4)pyz)(1/2), Me(4)pyz = tetramethylpyrazine, contains 2D sheets composed of Ag(tcm) 1D "tubes" linked by bridging Me(4)pyz ligands. Ag(tcm)(hmt), hmt = hexamethylenetetramine, has a 3D network structure in which the hmt ligands are 3-connecting, the tcm anions are 2-connecting, and the silver atoms are 5-connecting. The topology is the same as displayed by Ag(tcm)(L), L = dabco or bipy.

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PubMed2002

First Cu(II) diamondoid net with 2-fold interpenetrating frameworks. The role of anions in the construction of the supramolecular arrays.

The synthesis and crystal structure of the three-dimensional coordination polymer of an angular dipyridyl ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L) and Cu(ClO(4))(2), exhibiting the first Cu(II) diamondoid network with 2-fold interpenetration, ([Cu(L)(2)(H(2)O)(2)](ClO(4))(OH)(H(2)O)(2.5))(n) (1), together with the Cu(OAc)(2) complex of L, [Cu(L)(2)(OAc)(2)(H(2)O)](H(2)O)(2)(CH(3)OH) (2), with an unexpected mononuclear structure, are reported. Crystal data for 1: tetragonal, space group I4(1)/a, a = b = 13.477(3) A, c = 46.167(13) A, Z = 8. Crystal data for 2: triclinic, space group P(-)1, a = 7.847(2) A, b = 13.189(4) A, c = 15.948(5) A, alpha = 75.225(7) degrees, beta = 79.945(6) degrees, gamma = 77.540(5) degrees, Z = 2. The magnetic properties and anion effect are also discussed.

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