CXLIII.—Conductivity and ionisation of solutions of potassium iodide in nitromethane

Philip, James Charles; Oakley, Henry Bowen

doi:10.1039/ct9242501189

Cited by 16 publications

(7 citation statements)

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“…anions, all lying on general positions; a half-cation Fe(38)-Cl(58) (half-molecule B) spanning the C 2 axis [x, 1/4, 1/4], with Fe (38), N(39), C(42), N(49) and C(52) all lying on this axis; and, two half-anions lying on the C 2 axes [-1/4, 0, z] and [1/4, 0, z]. The pyrazole groups of both half-ligands in half-molecule B, N(43)-Cl (48) and N(53)-Cl(58), are disordered about two sites. The Fe-N distances to these groups imply that they correspond to resolved high-and low-spin fractions of the complex at this site.…”

Section: Single-crystal X-ray Structure Determinationsmentioning

confidence: 99%

“…Magnetic susceptibility measurements in solution were obtained by Evans method using a Bruker DRX500 spectrometer operating at 500.13 MHz. 47 A diamagnetic correction for the sample, 46 and a correction for the variation of the density of the CD 3 NO 2 solvent with temperature, 48 were applied to these data. All magnetochemical data manipulation was carried out using SIGMAPLOT.…”

Section: Other Measurementsmentioning

confidence: 99%

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Thermal and light-induced spin-transitions in iron(ii) complexes of 2,6-bis(4-halopyrazolyl)pyridines: the influence of polymorphism on a spin-crossover compound

et al. 2009

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The syntheses of 2,6-bis(4-chloropyrazol-1-yl)pyridine (L1), 2,6-bis(4-bromopyrazol-1-yl)pyridine (L2) and 2,6-bis(4-iodopyrazol-1-yl)pyridine (L3) by electrophilic halogenation of 2,6-bis(pyrazol-1-yl)pyridine are reported. The complex [Fe(L1)2][BF4]2 crystallises in two different solvent-free polymorphs. The tetragonal (alpha) form crystallises in a known version of the "terpyridine embrace" structure, and undergoes an abrupt spin-transition at 202 K. The orthorhombic (beta) form exhibits a modified form of the same packing motif, containing two unique iron sites in a 2 : 1 ratio. One-third of the complex molecules in that material undergo a very gradual thermal spin-crossover centred at 137 K. Comparison of the two structures implies that spin-crossover cooperativity in the alpha-polymorph is transmitted in two dimensions within the extended lattice. [Fe(L2)2][BF4]2 is isostructural with alpha-[Fe(L1)2][BF4]2 and exhibits a similarly abrupt spin-transition at 253 K. In contrast, [Fe(L3)2][BF4]2 is low-spin as a powder at 360 K and below and can be crystallised as two different solvates from acetone solution. All three compounds exhibit the LIESST effect at 10 K, with photoconversions of 40-100%. Their LIESST relaxation temperatures obey the empirical T(LIESST) = T0- 0.3T(1/2) (T0 = 150 K) law that we have previously proposed for this class of compound.

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Section: Single-crystal X-ray Structure Determinationsmentioning

confidence: 99%

Section: Other Measurementsmentioning

confidence: 99%

Thermal and light-induced spin-transitions in iron(ii) complexes of 2,6-bis(4-halopyrazolyl)pyridines: the influence of polymorphism on a spin-crossover compound

et al. 2009

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“…Magnetic susceptibility measurements in solution were obtained by Evans method using a Bruker DRX500 spectrometer operating at 500.13 MHz. [37] A diamagnetic correction for the sample, [39] and a correction for the variation of the density of the CD 3 NO 2 solvent with temperature, [40] were applied to these data.…”

Section: Methodsmentioning

confidence: 99%

A Back‐to‐Back Ligand with Dipyrazolylpyridine and Dipicolylamine Metal‐Binding Domains

et al. 2010

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Keywords: Iron / Palladium / N ligands / Bridging ligandsReaction of 4-bromomethyl-2,6-bis(pyrazol-1-yl)pyridine with dipicolylamine yields 4-bis(pyrid-2-ylmethyl)aminomethyl-2,6-bis(pyrazol-1-yl)pyridine (L). Treatment of L with [MCl 2 (NCPh) 2 ] (M = Pd, Pt) in the presence of AgPF 6 affords [MCl(L)]PF 6 , whose palladium or platinum centre is bound exclusively by the dipicolylamino moiety of L, as established by NMR spectroscopy. The pendant dipyrazolylpyridine residue in these compounds is complexed by

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“…Magnetic susceptibility measurements in solution were obtained by Evans method using a Bruker DRX500 spectrometer operating at 500.13 MHz. 53 A diamagnetic correction for the sample, 52 and a correction for the variation of the density of the CD 3 NO 2 solvent with temperature, 54 were applied to these data. All magnetochemical data manipulation was carried out using SIGMAPLOT.…”

Section: Other Measurementsmentioning

confidence: 99%

An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

et al. 2015

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The syntheses of 4-mercapto-2,6-di(pyrazol-1-yl)pyridine (bppSH) and bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]disulfide (bppSSbpp) are reported. In contrast to previously published "back-to-back" bis-[2,6-di(pyrazol-1-yl)pyridine] derivatives, which form coordination polymers with transition ions that are usually insoluble, bppSSbpp yields soluble oligomeric complexes with iron(ii) and zinc(ii). Mass spectrometry and DOSY data show that [{Fe(μ-bppSSbpp)}n](2n+) and [{Zn(μ-bppSSbpp)}n](2n+) form tetranuclear metallacycles in nitromethane solution (n = 4), although (1)H NMR and conductivity measurements imply the iron compound may undergo more fragmentation than its zinc congener. Both [{Fe(bppSH)2](2+) and [{Fe(μ-bppSSbpp)}n](2n+) exhibit thermal spin-crossover in CD3NO2 solution, with midpoint temperatures near 245 K. The similarity of these equilibria implies there is little cooperativity between the iron centres in the metallacyclic structures.

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CXLIII.—Conductivity and ionisation of solutions of potassium iodide in nitromethane

Cited by 16 publications

References 0 publications

Thermal and light-induced spin-transitions in iron(ii) complexes of 2,6-bis(4-halopyrazolyl)pyridines: the influence of polymorphism on a spin-crossover compound

Thermal and light-induced spin-transitions in iron(ii) complexes of 2,6-bis(4-halopyrazolyl)pyridines: the influence of polymorphism on a spin-crossover compound

A Back‐to‐Back Ligand with Dipyrazolylpyridine and Dipicolylamine Metal‐Binding Domains

An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

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