Scott Turner - Academia.edu (original) (raw)
Papers by Scott Turner
The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand ... more The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand (bppCONH2) is described. The complex salts [Fe(bppCONH2)2](BF4)2 and [Fe(bppCONH2)2](ClO4)2 were synthesised and characterised by SQUID magnetometry, differential scanning calorimetry, variable temperature Raman spectroscopy and single crystal X-ray diffraction. DSC measurements of [Fe(bppCONH2)2](BF4)2 indicate a spin-crossover (SCO) transition with T↑ at 481 K and T↓ at 461 K, showing a 20 K hysteresis. DSC for the perchlorate salt shows an SCO transition with T↑ at 459 K and T↓ at 445 K with a 14 K hysteresis. For the BF4- salt analysis of low and high-spin state crystal structures at 101, 290 and 500 K, suggest stabilisation of the low spin state due to the formation of 1D hydrogen-bonded cationic chains. Variable temperature Raman studies of the BF4 salt support the presence of a high temperature SCO. It is speculated that the presence of hysteresis may be attributed to differences ...
Magnetochemistry
Professor Peter Day FRS was born on 20 August 1938 in Kent (UK) and attended Maidstone Grammar Sc... more Professor Peter Day FRS was born on 20 August 1938 in Kent (UK) and attended Maidstone Grammar School [...]
Crystals
New bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-, bis(ethylenediseleno)tetrathiafulvalene (B... more New bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-, bis(ethylenediseleno)tetrathiafulvalene (BEST)- and bis(ethylenedithio)tetraselenafulvalene (BETS)-based organic charge-transfer (CT) salts—α-(BEDT-TTF)3(HOC2H4SO3)2 (1), β-(BEST)3(HOC2H4SO3)2·H2O (2) and α-(BETS)2(HOC2H4SO3)·H2O (3)—have been prepared. Salts 1 and 2 show semiconducting behaviour. Salt 3, which is almost isostructural to α-(BETS)2I3, shows metallic behaviour down to 70 K and then shows a broader metal–insulator transition than that of α-(BETS)2I3. The reason for the difference in behaviour is estimated by the comparison of the Madelung energies of the full set of patterns of possible donor’s charge-ordered and anion’s disordered states.
Journal of the Chemical Society, Faraday Transactions
The fluid solution EPR spectra of [VO(L)(µ- L1)VO(L)(dmpz)]· 2C6H5Me (I), [{VO(L)(dmpz)}2(µ- L2)]... more The fluid solution EPR spectra of [VO(L)(µ- L1)VO(L)(dmpz)]· 2C6H5Me (I), [{VO(L)(dmpz)}2(µ- L2)]· 2MeCN · 2H2O (II) and [{VO(L)(dmpz)}2(µ- L3)]· 1.2C6H5Me (III)[L = hydrotris(3,5- dimethylpyrazolyl)borato, H2L1= malonic acid, H2L2= acetylenedicarboxylic acid, H2L3= benzene- 1,4-dicarboxylic acid, dmpz = 3,5- dimethylpyrazole] in CH2Cl2, CH2Cl2–toluene, CH2Cl2–MeCN and CH2Cl2–MeOH mixtures, at X-band frequency, and over the temperature range 300–240 K are reported. The spectra are consistent with the dimeric formulations wherein there is an exchange interaction with |J|/|A > 1. In addition, the spectra exhibit unusual amplitude variations of the lines which are attributed to fluctuations in the exchange interactions.
[
Physica B: Condensed Matter
We have prepared new organic anionic acceptors, Br2XQNHCH2SO3− (2: X=Br, 3: X=BryCl1−y (y≈0.5), 4... more We have prepared new organic anionic acceptors, Br2XQNHCH2SO3− (2: X=Br, 3: X=BryCl1−y (y≈0.5), 4: X=Cl; Q=1,4-benzoquinone), that possess both an electron acceptor part (1,4-benzoquinone) and an anionic part (sulfonate). The reduction potentials of the PPh4 salts of 2, 3 and 4 are −0.45, −0.45 and −0.46V (vs. SCE in CH3CN), respectively. The results indicate that they are weaker acceptors than chloranil (−0.13V) and bromanil (−0.12V). Each anionic acceptor (AA) provided two BEDT-TTF salts, β-(ET)5(AA)2·DCE·zH2O and λ-(ET)2(AA)·CH3OH (AA=2, 3, or 4; z=2: 0.97, 3: 0.83 and 4: 0.40). The structures and transport properties of the salts are reported.
![Research paper thumbnail of New Dmit-Based Organic Magnetic Conductors (PO-CONH-C2H4N(CH3)3)[M(dmit)2]2 (M = Ni, Pd) Including an Organic Cation Derived from a 2,2,5,5-Tetramethyl-3-pyrrolin-1-oxyl (PO) Radical](https://attachments.academia-assets.com/76789557/thumbnails/1.jpg)
](Magnetochemistry
We have prepared two dmit-based salts with a stable organic radical-substituted ammonium cation, ... more We have prepared two dmit-based salts with a stable organic radical-substituted ammonium cation, (PO-CONH-C 2 H 4 N(CH 3) 3)[Ni(dmit) 2 ] 2 •CH 3 CN and (PO-CONH-C 2 H 4 N(CH 3) 3)[Pd(dmit) 2 ] 2 where PO is 2,2,5,5-Tetramethyl-3-pyrrolin-1-oxyl and dmit is 2-Thioxo-1,3-dithiol-4,5-dithiolate. The salts are not isostructural but have similar structural features in the anion and cation packing arrangements. The acceptor layers of both salts consist of tetramers, which gather to form 2D conducting layers. Magnetic susceptibility measurements indicate that the Ni salt is a Mott insulator and the Pd salt is a band insulator, which has been confirmed by band structure calculations. The cationic layers of both salts have a previously unreported polar structure, in which the cation dipoles order as ÀÄÀÄ along the acceptors stacking direction to provide dipole moments. The dipole moments of nearest neighbor cation layers are inverted in both salts, indicating no net dipole moments for the whole crystals. The magnetic network of the [Ni(dmit) 2 ] layer of the Ni salt is two-dimensional so that the magnetic susceptibility would be expected to obey the 1D or 2D Heisenberg model that has a broad maximum around T ≈ θ. However, the magnetic susceptibility after subtraction of the contribution from the PO radical has no broad maximum. Instead, it shows Curie-Weiss behavior with C = 0.378 emu•K/mol and θ = −35.8 K. The magnetic susceptibility of the Pd salt obeys a Curie-Weiss model with C = 0.329 emu•K•mol −1 and θ = −0.88 K.
Journal of Materials Chemistry 15 23 25, 2005
Inorganic Chemistry, Oct 15, 2007
A new bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with a ferrocenyl moiety, R′′′-... more A new bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with a ferrocenyl moiety, R′′′-(BEDT-TTF) 4 (Fe(C 5 H 4 SO 3) 2)‚6H 2 O, has been prepared. The ferrocenyl part of this salt is neutral and diamagnetic, but the magnetic susceptibility is well modeled by a Curie−Weiss law with C) 0.142 emu‚K‚mol-1 (≈ 1 / 3 of s) 1 / 2 spin). The spin is likely to be localized on the donor layer because of its unique charge disproportionation. Charge-transfer salts of the electron donor molecule bis-(ethylenedithio)tetrathiafulvalene (BEDT-TTF) exhibit a wide range of ground states, including metallic, superconducting, semiconducting, or insulating. 1a Typically, their structures consist of stacks of positively charged BEDT-TTF molecules that form layers that are interleaved by layers of counterions. The donor molecules pack in a variety of ways, leading to phases that are designated by the letters R, , γ, κ, λ, etc. 1,2 Evidently, the packing motifs play a crucial role in determining the electronic ground states. However, salts that have the same packing motif but different counteranions often have different ground states. In other words, additional structural subtlety can modify the ground states. 1a,d Recently, insulating states have been of interest to many researchers and various types of insulating states have been established, 1 such as charge-density wave, spin-density wave, Mott
A novel bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with an aminoxyl radical 2,2,... more A novel bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with an aminoxyl radical 2,2,5,5-tetramethyl-3-pyrrolin-1-oxyl (PO) has been prepared. The salt has α-type 2-D conducting sheets and is a semiconductor with ρ = 26 Ω·cm and E = 0.31 eV. The temperature dependence of the magnetic susceptibility suggests that both the aminoxyl radical and the BEDT-TTF layer have local spin moments at room temperature. Copyright © 2008 The Chemical Society of Japan.
![Research paper thumbnail of Preparation, magnetic properties and crystal structure of bis[3-(4-pyridyl)pentane-2,4-dionato]copper(II)](https://attachments.academia-assets.com/76789564/thumbnails/1.jpg)
](Journal of the Chemical Society, Dalton Transactions, 1997
Preparation, magnetic properties and crystal structure of bis[3-(4-pyridyl)pentane-2,4-dionato]co... more Preparation, magnetic properties and crystal structure of bis[3-(4-pyridyl)pentane-2,4-dionato]copper(II)
Crystals, 2012
A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a s... more A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a strong electron acceptor. The reduction potential of the PPh 4 salt indicates that 1 is a stronger acceptor than DDQ (2,3-dichloro-5,6-dicyano-1,4benzoquinone). The dianionic acceptor provided a BEDT-TTF salt, (BEDT-TTF) 4 1• 3H 2 O, the structures and physical properties of which are reported.
Organometallics, 2015
Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N−O) were unsucce... more Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N−O) were unsuccessful, and only small amounts of the trivalent tris complexes M(N− O) 3 were detected, although unusually in the case of Fe(III) a fac structure is observed. In contrast the 2-benzoylpyrrolyl systems give M(II) complexes, and in all instances thus far where Na + is present, a scorpionate fac-[M II (N−O) 3 ] − unit selfassembles into sandwich anions [M II (N−O) 3 Na(O−N) 3 M II ] − in which the central metal is efficiently encapsulated by interdigitation of the aryl units. Extended structures are readily made through the use of a 2-(4-pyridinoyl)pyrrolylamide ligand. When Li + is used, the scorpionate ligand is not assembled, and instead [M(N−O) 2 ] units give rhombic 2D grids. The Fe system displays spin-crossover at 120 K.
Synthetic Metals, 2001
ABSTRACT
We present a spin resonance investigation of the family of quasi- two-dimensional organic (super)... more We present a spin resonance investigation of the family of quasi- two-dimensional organic (super)conductors ''circ; -(ET)4-[(H3-O)M-(C2-O4)3]S (M = Cr^ 3+, Fe^3+; S is a guest molecule). The spin systems are probed by means of both resonant cavity perturbation and field modulation techniques in the frequency range 50-313 GHz. The role of the different solvent molecules in determining the degree of spin-orbit coupling and the local symmetry at the metal ion site is established. Intensities, positions and widths of the resonant lines reveal significant modifications of the spin-orbit coupling, and of the inter- and intra-ionic spin-spin interactions below T=10K. Despite the onset of a weak antiferromagnetic internal field at low temperature, the ultimate narrowing of the lines suggests spin-lattice interactions are still the dominant relaxation process. Additional lineshifts observed below B = 2.5 T and T = 4 K, attributed to the presence of diamagnetic currents in the mixed s...
A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is... more A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a strong electron acceptor. The reduction potential of the PPh4 salt indicates that 1 is a stronger acceptor than DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone). The dianionic acceptor provided a BEDT-TTF salt, (BEDT-TTF)41·3H2O, the structures and physical properties of which are reported.
![Research paper thumbnail of Self-assembly preparation, structure and magnetic studies of a novel dinuclear copper(II) complex: [Cu2(μ-OH)(μ-OAc)(μ-L)][BF4]2 [L = bis-1,3-(cis,cis-1,3,5-triaminocyclohexane)xylylidiene]](https://attachments.academia-assets.com/76789559/thumbnails/1.jpg)
](Journal of the Chemical Society, Dalton Transactions, 1998
Self-assembly preparation, structure and magnetic studies of a novel dinuclear copper(II) complex... more Self-assembly preparation, structure and magnetic studies of a novel dinuclear copper(II) complex: [Cu 2 (-OH)(-OAc)(-L)][BF 4 ] 2 [L ؍ bis-1,3-(cis,cis-1,3,5-triaminocyclohexane)xylylidiene]
X-ray Structure Analysis Online, 2013
Chemistry N,N¢-Dicyanoquinonediimines (DCNQI, Fig. 1) are one of the most well-known electron acc... more Chemistry N,N¢-Dicyanoquinonediimines (DCNQI, Fig. 1) are one of the most well-known electron acceptors. They have provided conducting charge-transfer (CT) complexes and radical anion salts, which have attracted worldwide interest. 1 For example, (DMeDCNQI)2Cu (Fig. 1) shows an unusual reentrant metalinsulator-metal transition. These types of salts are usually prepared via an electrochemical method. Alternatively, they may be obtained by chemical reactions of DMeDCNQI with CuI in organic solvents, in which the DMeDCNQI acceptor is reduced by the CuI. 2 Recently, we prepared a new anionic acceptor, N,N¢-disulfobenzoquinone diimines [dsqi (1)], which has two-SO3groups instead of the two-CN groups of DCNQI. 1 is a dianion and also an electron acceptor, by virtue of the-SO3groups and an acceptor part, the quinodiimine skeleton. This anion has been used as the counteranion of a BEDT-TTFbased CT salt [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene]. 3 However, until now no attempt was made to prepare its Cu complex, which we report in this paper.
The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand ... more The synthesis of a novel amide-functionalised 2,6-bis(pyrazol-1-yl)pyridine-4-carboxamide ligand (bppCONH2) is described. The complex salts [Fe(bppCONH2)2](BF4)2 and [Fe(bppCONH2)2](ClO4)2 were synthesised and characterised by SQUID magnetometry, differential scanning calorimetry, variable temperature Raman spectroscopy and single crystal X-ray diffraction. DSC measurements of [Fe(bppCONH2)2](BF4)2 indicate a spin-crossover (SCO) transition with T↑ at 481 K and T↓ at 461 K, showing a 20 K hysteresis. DSC for the perchlorate salt shows an SCO transition with T↑ at 459 K and T↓ at 445 K with a 14 K hysteresis. For the BF4- salt analysis of low and high-spin state crystal structures at 101, 290 and 500 K, suggest stabilisation of the low spin state due to the formation of 1D hydrogen-bonded cationic chains. Variable temperature Raman studies of the BF4 salt support the presence of a high temperature SCO. It is speculated that the presence of hysteresis may be attributed to differences ...
Magnetochemistry
Professor Peter Day FRS was born on 20 August 1938 in Kent (UK) and attended Maidstone Grammar Sc... more Professor Peter Day FRS was born on 20 August 1938 in Kent (UK) and attended Maidstone Grammar School [...]
Crystals
New bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-, bis(ethylenediseleno)tetrathiafulvalene (B... more New bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-, bis(ethylenediseleno)tetrathiafulvalene (BEST)- and bis(ethylenedithio)tetraselenafulvalene (BETS)-based organic charge-transfer (CT) salts—α-(BEDT-TTF)3(HOC2H4SO3)2 (1), β-(BEST)3(HOC2H4SO3)2·H2O (2) and α-(BETS)2(HOC2H4SO3)·H2O (3)—have been prepared. Salts 1 and 2 show semiconducting behaviour. Salt 3, which is almost isostructural to α-(BETS)2I3, shows metallic behaviour down to 70 K and then shows a broader metal–insulator transition than that of α-(BETS)2I3. The reason for the difference in behaviour is estimated by the comparison of the Madelung energies of the full set of patterns of possible donor’s charge-ordered and anion’s disordered states.
Journal of the Chemical Society, Faraday Transactions
The fluid solution EPR spectra of [VO(L)(µ- L1)VO(L)(dmpz)]· 2C6H5Me (I), [{VO(L)(dmpz)}2(µ- L2)]... more The fluid solution EPR spectra of [VO(L)(µ- L1)VO(L)(dmpz)]· 2C6H5Me (I), [{VO(L)(dmpz)}2(µ- L2)]· 2MeCN · 2H2O (II) and [{VO(L)(dmpz)}2(µ- L3)]· 1.2C6H5Me (III)[L = hydrotris(3,5- dimethylpyrazolyl)borato, H2L1= malonic acid, H2L2= acetylenedicarboxylic acid, H2L3= benzene- 1,4-dicarboxylic acid, dmpz = 3,5- dimethylpyrazole] in CH2Cl2, CH2Cl2–toluene, CH2Cl2–MeCN and CH2Cl2–MeOH mixtures, at X-band frequency, and over the temperature range 300–240 K are reported. The spectra are consistent with the dimeric formulations wherein there is an exchange interaction with |J|/|A > 1. In addition, the spectra exhibit unusual amplitude variations of the lines which are attributed to fluctuations in the exchange interactions.
[
Physica B: Condensed Matter
We have prepared new organic anionic acceptors, Br2XQNHCH2SO3− (2: X=Br, 3: X=BryCl1−y (y≈0.5), 4... more We have prepared new organic anionic acceptors, Br2XQNHCH2SO3− (2: X=Br, 3: X=BryCl1−y (y≈0.5), 4: X=Cl; Q=1,4-benzoquinone), that possess both an electron acceptor part (1,4-benzoquinone) and an anionic part (sulfonate). The reduction potentials of the PPh4 salts of 2, 3 and 4 are −0.45, −0.45 and −0.46V (vs. SCE in CH3CN), respectively. The results indicate that they are weaker acceptors than chloranil (−0.13V) and bromanil (−0.12V). Each anionic acceptor (AA) provided two BEDT-TTF salts, β-(ET)5(AA)2·DCE·zH2O and λ-(ET)2(AA)·CH3OH (AA=2, 3, or 4; z=2: 0.97, 3: 0.83 and 4: 0.40). The structures and transport properties of the salts are reported.
Magnetochemistry
We have prepared two dmit-based salts with a stable organic radical-substituted ammonium cation, ... more We have prepared two dmit-based salts with a stable organic radical-substituted ammonium cation, (PO-CONH-C 2 H 4 N(CH 3) 3)[Ni(dmit) 2 ] 2 •CH 3 CN and (PO-CONH-C 2 H 4 N(CH 3) 3)[Pd(dmit) 2 ] 2 where PO is 2,2,5,5-Tetramethyl-3-pyrrolin-1-oxyl and dmit is 2-Thioxo-1,3-dithiol-4,5-dithiolate. The salts are not isostructural but have similar structural features in the anion and cation packing arrangements. The acceptor layers of both salts consist of tetramers, which gather to form 2D conducting layers. Magnetic susceptibility measurements indicate that the Ni salt is a Mott insulator and the Pd salt is a band insulator, which has been confirmed by band structure calculations. The cationic layers of both salts have a previously unreported polar structure, in which the cation dipoles order as ÀÄÀÄ along the acceptors stacking direction to provide dipole moments. The dipole moments of nearest neighbor cation layers are inverted in both salts, indicating no net dipole moments for the whole crystals. The magnetic network of the [Ni(dmit) 2 ] layer of the Ni salt is two-dimensional so that the magnetic susceptibility would be expected to obey the 1D or 2D Heisenberg model that has a broad maximum around T ≈ θ. However, the magnetic susceptibility after subtraction of the contribution from the PO radical has no broad maximum. Instead, it shows Curie-Weiss behavior with C = 0.378 emu•K/mol and θ = −35.8 K. The magnetic susceptibility of the Pd salt obeys a Curie-Weiss model with C = 0.329 emu•K•mol −1 and θ = −0.88 K.
Journal of Materials Chemistry 15 23 25, 2005
Inorganic Chemistry, Oct 15, 2007
A new bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with a ferrocenyl moiety, R′′′-... more A new bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with a ferrocenyl moiety, R′′′-(BEDT-TTF) 4 (Fe(C 5 H 4 SO 3) 2)‚6H 2 O, has been prepared. The ferrocenyl part of this salt is neutral and diamagnetic, but the magnetic susceptibility is well modeled by a Curie−Weiss law with C) 0.142 emu‚K‚mol-1 (≈ 1 / 3 of s) 1 / 2 spin). The spin is likely to be localized on the donor layer because of its unique charge disproportionation. Charge-transfer salts of the electron donor molecule bis-(ethylenedithio)tetrathiafulvalene (BEDT-TTF) exhibit a wide range of ground states, including metallic, superconducting, semiconducting, or insulating. 1a Typically, their structures consist of stacks of positively charged BEDT-TTF molecules that form layers that are interleaved by layers of counterions. The donor molecules pack in a variety of ways, leading to phases that are designated by the letters R, , γ, κ, λ, etc. 1,2 Evidently, the packing motifs play a crucial role in determining the electronic ground states. However, salts that have the same packing motif but different counteranions often have different ground states. In other words, additional structural subtlety can modify the ground states. 1a,d Recently, insulating states have been of interest to many researchers and various types of insulating states have been established, 1 such as charge-density wave, spin-density wave, Mott
A novel bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with an aminoxyl radical 2,2,... more A novel bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with an aminoxyl radical 2,2,5,5-tetramethyl-3-pyrrolin-1-oxyl (PO) has been prepared. The salt has α-type 2-D conducting sheets and is a semiconductor with ρ = 26 Ω·cm and E = 0.31 eV. The temperature dependence of the magnetic susceptibility suggests that both the aminoxyl radical and the BEDT-TTF layer have local spin moments at room temperature. Copyright © 2008 The Chemical Society of Japan.
Journal of the Chemical Society, Dalton Transactions, 1997
Preparation, magnetic properties and crystal structure of bis[3-(4-pyridyl)pentane-2,4-dionato]co... more Preparation, magnetic properties and crystal structure of bis[3-(4-pyridyl)pentane-2,4-dionato]copper(II)
Crystals, 2012
A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a s... more A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a strong electron acceptor. The reduction potential of the PPh 4 salt indicates that 1 is a stronger acceptor than DDQ (2,3-dichloro-5,6-dicyano-1,4benzoquinone). The dianionic acceptor provided a BEDT-TTF salt, (BEDT-TTF) 4 1• 3H 2 O, the structures and physical properties of which are reported.
Organometallics, 2015
Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N−O) were unsucce... more Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N−O) were unsuccessful, and only small amounts of the trivalent tris complexes M(N− O) 3 were detected, although unusually in the case of Fe(III) a fac structure is observed. In contrast the 2-benzoylpyrrolyl systems give M(II) complexes, and in all instances thus far where Na + is present, a scorpionate fac-[M II (N−O) 3 ] − unit selfassembles into sandwich anions [M II (N−O) 3 Na(O−N) 3 M II ] − in which the central metal is efficiently encapsulated by interdigitation of the aryl units. Extended structures are readily made through the use of a 2-(4-pyridinoyl)pyrrolylamide ligand. When Li + is used, the scorpionate ligand is not assembled, and instead [M(N−O) 2 ] units give rhombic 2D grids. The Fe system displays spin-crossover at 120 K.
Synthetic Metals, 2001
ABSTRACT
We present a spin resonance investigation of the family of quasi- two-dimensional organic (super)... more We present a spin resonance investigation of the family of quasi- two-dimensional organic (super)conductors ''circ; -(ET)4-[(H3-O)M-(C2-O4)3]S (M = Cr^ 3+, Fe^3+; S is a guest molecule). The spin systems are probed by means of both resonant cavity perturbation and field modulation techniques in the frequency range 50-313 GHz. The role of the different solvent molecules in determining the degree of spin-orbit coupling and the local symmetry at the metal ion site is established. Intensities, positions and widths of the resonant lines reveal significant modifications of the spin-orbit coupling, and of the inter- and intra-ionic spin-spin interactions below T=10K. Despite the onset of a weak antiferromagnetic internal field at low temperature, the ultimate narrowing of the lines suggests spin-lattice interactions are still the dominant relaxation process. Additional lineshifts observed below B = 2.5 T and T = 4 K, attributed to the presence of diamagnetic currents in the mixed s...
A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is... more A novel organic dianion, N,N'-Disulfo-1,4-benzoquinonediimine (1) has been prepared, which is a strong electron acceptor. The reduction potential of the PPh4 salt indicates that 1 is a stronger acceptor than DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone). The dianionic acceptor provided a BEDT-TTF salt, (BEDT-TTF)41·3H2O, the structures and physical properties of which are reported.
Journal of the Chemical Society, Dalton Transactions, 1998
Self-assembly preparation, structure and magnetic studies of a novel dinuclear copper(II) complex... more Self-assembly preparation, structure and magnetic studies of a novel dinuclear copper(II) complex: [Cu 2 (-OH)(-OAc)(-L)][BF 4 ] 2 [L ؍ bis-1,3-(cis,cis-1,3,5-triaminocyclohexane)xylylidiene]
X-ray Structure Analysis Online, 2013
Chemistry N,N¢-Dicyanoquinonediimines (DCNQI, Fig. 1) are one of the most well-known electron acc... more Chemistry N,N¢-Dicyanoquinonediimines (DCNQI, Fig. 1) are one of the most well-known electron acceptors. They have provided conducting charge-transfer (CT) complexes and radical anion salts, which have attracted worldwide interest. 1 For example, (DMeDCNQI)2Cu (Fig. 1) shows an unusual reentrant metalinsulator-metal transition. These types of salts are usually prepared via an electrochemical method. Alternatively, they may be obtained by chemical reactions of DMeDCNQI with CuI in organic solvents, in which the DMeDCNQI acceptor is reduced by the CuI. 2 Recently, we prepared a new anionic acceptor, N,N¢-disulfobenzoquinone diimines [dsqi (1)], which has two-SO3groups instead of the two-CN groups of DCNQI. 1 is a dianion and also an electron acceptor, by virtue of the-SO3groups and an acceptor part, the quinodiimine skeleton. This anion has been used as the counteranion of a BEDT-TTFbased CT salt [BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene]. 3 However, until now no attempt was made to prepare its Cu complex, which we report in this paper.