Interpersonal violence and mental health outcomes following disaster.

BACKGROUND: Disasters pose a documented risk to mental health, with a range of peri- and post-disaster factors (both pre-existing and disaster-precipitated) linked to adverse outcomes. Among these, increasing empirical attention is being paid to the relation between disasters and violence. AIMS: This study examined self-reported experiences of assault or violence victimisation among communities affected by high, medium, and low disaster severity following the 2009 bushfires in Victoria, Australia. The association between violence, mental health outcomes and alcohol misuse was also investigated. METHOD: Participants were 1016 adults from high-, medium- and low-affected communities, 3-4 years after an Australian bushfire disaster. Rates of reported violence were compared by areas of bushfire-affectedness. Logistic regression models were applied separately to men and women to assess the experience of violence in predicting general and fire-related post-traumatic stress disorder, depression and alcohol misuse. RESULTS: Reports of experiencing violence were significantly higher among high bushfire-affected compared with low bushfire-affected regions. Analyses indicated the significant relationship between disaster-affectedness and violence was observed for women only, with rates of 1.0, 0 and 7.4% in low, medium and high bushfire-affected areas, respectively. Among women living in high bushfire-affected areas, negative change to income was associated with an increased likelihood of experiencing violence (odds ratio, 4.68). For women, post-disaster violence was associated with more severe post-traumatic stress disorder and depression symptoms. CONCLUSIONS: Women residing within high bushfire-affected communities experienced the highest levels of violence. These post-disaster experiences of violence are associated with post-disaster changes to income and with post-traumatic stress disorder and depression symptoms among women. These findings have critical implications for the assessment of, and interventions for, women experiencing or at risk of violence post-disaster.

Mn(II) and Cu(II) complexes of a dithiadiazolyl radical ligand: monomer/dimer equilibria in solution.

Complexes of the 4-(2'-pyridyl)-1,2,3,5-dithiadiazolyl radical bidentate ligand with bis(hexafluoroacetylacetonato)manganese(II) and with bis(hexafluoroacetylacetonato)copper(II) have been prepared. Unlike the previously reported cobalt(II) complex, these complexes form dimers via intermolecular S...S contacts in the solid state. The spectroscopic and magnetic properties of these species in the solid state and in solution are reported and compared to the previously reported Co(II) complex, with emphasis on the elucidation of the a monomer/dimer equilibrium in the solution. The electrochemical properties of these species in solution are also presented and discussed.

Isostructural bisdithiazolyl and bisthiaselenazolyl radicals: trends in bandwidth and conductivity.

Reaction of N-alkylated pyridine-bridged bisdithiazolylium cations [1]+ (R1 =Me, Et; R2 =Ph) with selenium dioxide in acetic acid provides a one-step high-yield synthetic route to bisthiaselenazolylium cations [2]+ (R1 = Me, Et; R2 = Ph). The corresponding radicals 1 and 2 can be prepared by chemical or electrochemical reduction of the cations. Structural analysis of the radicals has been achieved by a combination of single-crystal and powder X-ray diffraction methods. While the two sulfur radicals 1 adopt different space groups (P3(1)21 for R1 = Me and P(-)1 for R1 = Et), the two selenium radicals 2 (space groups P3(1)21 for R1 = Me and P3(2)21 for R1 =Et) are isostructural with each other and also with 1 (R1 = Me, R2 = Ph). Variable-temperature magnetic measurements on all four compounds confirm that they are undimerized S = 1/2 systems, with varying degrees of weak intermolecular antiferromagnetic coupling. Variable-temperature electrical conductivity measurements on the two selenium radicals provide conductivities sigma(300 K) = 7.4 x 10-6 (R1 = Et) and 3.3 x 10-5 S cm-1 (R1 = Me), with activation energies, E(act), of 0.32 (R1 = Et) and 0.29 eV (R1 = Me). The differences in conductivity within the isostructural series is interpreted in terms of their relative solid-state bandwidths, as estimated from Extended Hückel band-structure calculations.

Bimodal association of a bis-1,2,3-dithiazolyl radical.

The N-ethyl pyrazine-bridged bis-1,2,3-dithiazolyl radical (R(1) = Et) associates at room temperature as a C-C bonded sigma-dimer which, on heating, converts to a laterally S-S sigma-bonded structure.

Pressure enhanced conductivity in bis-1,2,3-thiaselenazolyl dimers.

A synthetic sequence to salts of N-alkylated pyridine-bridged 1,2,3-thiaselenazolo-1,2,3-thiaselenazolylium cations [2]+ (R1 = Me, Et; R2 = H) is described. The corresponding radicals 2 (R1 = Me, Et; R2 = H) can be generated from the cations by chemical or electrochemical reduction. Crystals of the two radicals are isostructural and consist of interpenetrating pi-stacked arrays of closed-shell Se-Se sigma-bonded dimers [2]2 laced together with numerous short intermolecular Se- - -Se, Se- - -S, and Se- - -N contacts. Variable-temperature magnetic, conductivity, and near-infrared optical measurements indicate that the bulk materials behave as small band gap semiconductors with room-temperature conductivities sigma(RT) near 10(-6) S cm(-1) and thermal activation energies Ea of 0.32 eV (R1 = Me) and 0.36 eV (R1 = Et). LMTO band structure calculations on both compounds are consistent with this interpretation. The application of external pressure leads to dramatic increases in conductivity; at 4 GPa sigma(RT) reaches a value near 10(-1) S cm(-1) for R1 = Me and 10(-2) S/cm for R1 = Et. The conductivity remains activated for both compounds, but for R1 = Me the activation energy Ea is reduced to near 0.03 eV at 5 GPa, suggestive of a weakly metallic state.

The effect of selenium incorporation on the bandwidth and conductivity of neutral radical conductors.

The first example of an undimerized pi-stacked bis-1,2,3-thiaselenazolyl radical displays improved bandwidth and conductivity relative to an isostructural bis-1,2,3-dithiazolyl.

Naphthalene-1,2,3-dithiazolyl and its selenium-containing variants.

Synthetic routes to salts of the 3H-naphtho[1,2-d][1,2,3]dithiazolylium cation and its three selenium-containing variants (SSeN, SeSN, and SeSeN) are described. The most efficient and general method involves the intermediacy of bis-acetylated aminothiolates and aminoselenolates. These reagents react smoothly with sulfur and selenium halides to afford the desired ring closure products. Electrochemical reduction of the four cations indicates that corresponding radicals (SSN, SSeN, SeSN, and SeSeN) are stable in solution. The EPR spectra of all four have been recorded, and experimental spin distributions have been cross-matched with those obtained from DFT calculations. The selenium-containing radicals are thermally unstable at or slightly above room temperature, but the all-sulfur species has been isolated and characterized crystallographically. In the solid state, the radicals are associated into cofacial dimers which are closely linked to other dimers by intermolecular S---S, S---N, and C-H---aromatic ring interactions.

Bis-1,2,3-thiaselenazolyl radicals and their sigma-bonded dimers.

Resonance stabilized bis-1,2,3-thiaselenazolyl radicals associate in the solid state to afford Se-Se sigma-bonded dimers.

Resonance stabilized bis-thiadiazinyl radicals.

The resonance stabilized bis-thiadiazinyl framework holds potential as a stable and versatile building block for the design of radical-based conductors and magnetic materials.

Bistability and the phase transition in 1,3,2-dithiazolo[4,5-b]pyrazin-2-yl.

The molecular radical 1,3,2-dithiazolo[4,5-b]pyrazin-2-yl (PDTA) exhibits magnetic bistability just above room temperature, undergoing a well-defined hysteretic phase change with TC downward arrow = 297(1) K and TC upward arrow = 343(1) K. The crystal structures of the two phases of PDTA have been determined by single-crystal X-ray diffraction at 323(2) K. LT-PDTA consists of diamagnetic (S = 0) nearly superimposed pi-dimer stacks, while that of HT-PDTA comprises slipped stacks of pi-radicals (S = 1/2). The structural interconversion is suggested to proceed via the cooperative breaking and making of intermolecular S- - -N interactions and an inversion symmetry-preserving "domino cascade" of the pi-stacked rings.

Design and synthesis of a 4-(2'-pyridyl)-1,2,3,5-dithiadiazolyl cobalt complex.

The 4-(2'-pyridyl)-1,2,3,5-dithiadiazolyl neutral radical 1 has been prepared for use as a spin-bearing bidentate ligand. The coordination of this ligand to bis(hexafluoroacetylacetonato)cobalt affords a thermally stable complex 2. Magnetic susceptibility measurements of the crystalline complex indicate ferromagnetic coupling between the ligand-centered spin and the unpaired electrons of the high-spin Co(II).

Bistabilities in 1,3,2-dithiazolyl radicals.

New synthetic methods for heterocyclic 1,3,2-dithiazolyl (DTA) radicals have been developed, and trends in the molecular spin distributions and electrochemical properties of a series of DTA radicals are reported. The crystal structures of [1,2,5]thiadiazolo[3,4-f][1,3,2]benzodithiazol-2-yl (TBDTA) and [1,3,2]pyrazinodithiazol-2-yl (PDTA) have been determined. The structure of TBDTA (at 293 and 95 K) contains two molecules in the asymmetric unit, each of which generates pi-stacked arrays, one consisting of antiparallel chains of centrosymmetrically associated dimers, the other comprising parallel chains of unassociated radicals. The structure of PDTA (at 293 and 95 K) is simpler, consisting of slipped stacks of pi-dimers. Variable-temperature magnetic susceptibility (chi(P)) measurements on TBDTA indicate essentially paramagnetic behavior for the unassociated radical pi-stacks over the range 5-400 K. By contrast PDTA is diamagnetic at all temperatures below 300 K, but between 300 and 350 K the value of chi(P) follows a sharp and well-defined hysteresis loop, with T(C) downward arrow = 297 K and T(C) upward arrow = 343 K. These features are symptomatic of a regime of bistability involving the observed low temperature pi-dimer structure and a putative high-temperature radical pi-stack. A mechanism for the interconversion of the two phases of PDTA and related structures is proposed in which hysteretic behavior arises from cooperative effects associated with the breaking and making of a lattice-wide network of intermolecular S- - -N' and/or S- - -S' interactions.

Solid-state NMR and calorimetry of structural waters in helical peptides.

The peptide hydrates Gly-Gly-Val x 2H(2)O (GGV) and Gly-Ala-Leu x 3H(2)O (GAL) are known to adopt alpha-helical configurations containing waters of hydration in which each water is H-bonded to three or four peptide groups. Herein we report a thermodynamic and solid-state NMR ((2)H and (17)O) study of these peptides. From TGA and DSC, the average enthalpy per H-bond is 15 kJ/mol. The dynamics and average orientation of the hydrate are studied by powder and single-crystal (2)H NMR. Whereas waters that are shown by the X-ray structure to be coordinated by four hydrogen bonds do not yield observable (2)H NMR signals at room temperature, two of the three triply coordinated waters yield residual (2)H quadrupole coupling tensors characteristic of rapid 180 degrees flip motions and the orientation of the residual tensor is that expected from the X-ray structure-derived H-bonding pattern. At -65 degrees C, the flip motions of triply coordinated water in GGV slow into the (2)H NMR intermediate exchange regime whereas the tetrahedrally coordinated water approaches the slow-exchange limit and yields an observable NMR signal. Extensive isotope exchange between water vapor and crystalline GGV establishes the presence of additional hydrate dynamics and solid-state proton transfer along a chain of water-bridged protonated alpha-amino groups.

Activation of Ligand Reactivity: Thiolate C-S and Dithiophosphate Ester C-O Heterolyses within a Dimolybdenum(V) System.

Ligand reactivity was demonstrated for sulfide alkylation, thiolate dealkylation, and dithiophosphate de-esterification within molybdenum(V) dimers. The cationic complex [Mo(2)(NC(6)H(4)Me)(2)(S(2)P(OEt)(2))(2)(&mgr;-O(2)CMe)(&mgr;-SR)(2)](+) was inductively activated toward thiolate C-S and dithiophosphate C-O heterolyses. The dealkylations were studied using anionic nucleophiles, and various reactivity patterns were characterized. The de-esterification of the diethyl dithiophosphate ligands produced complexes containing the rare monoester EtO(O)PS(2)(2)(-) ligand. This ligand's phosphoryl group was poorly nucleophilic but weakly basic. Crystallographic comparisons between the activated cation and the neutral complex [Mo(2)(NC(6)H(4)Me)(2)(S(2)P(OEt)(2))(2)(&mgr;-O(2)CMe)(&mgr;-S)(&mgr;-SMe)] were conducted to delineate structural differences related to the activation. A crystallographic study was also done of the complex [Mo(2)(NC(6)H(4)CH(3))(2)(S(2)P(OEt)(2))(S(2)P(O)OEt)(&mgr;-O(2)CMe)(&mgr;-SEt)(2)], which provided internal comparison of monoester EtO(O)PS(2)(2)(-) and diester (EtO)(2)PS(2)(-) ligand types.

Dinuclear Copper(II) Complexes Incorporating a New Septadentate Polyimidazole Ligand.

The dinuclear copper(II) complexes [Cu(2)(tmihpn)(prz)](ClO(4))(2).2CH(3)CN (6) and [Cu(2)(tmihpn)(O(2)CCH(3))](ClO(4))(2).CH(3)CN (7) were prepared, where tmihpn is the deprotonated form of N,N,N',N'-tetrakis[(1-methylimidazol-2-yl)methyl]-1,3-diaminopropan-2-ol and prz is the pyrazolate anion. The crystal structures of 6 and 7 were determined and revealed that both complexes contain bridging alkoxide ligands as well as bridging pyrazolate and acetate ions, respectively. Crystal data: compound 6, triclinic, P&onemacr;, a = 18.089(2) Å, b = 22.948(3) Å, c = 9.597(2) Å, alpha = 93.37(2) degrees, beta = 94.49(2) degrees, gamma = 81.69(2) degrees, V = 3925.1 Å(3), Z = 4; compound 7, triclinic, P&onemacr;, a = 12.417(2) Å, b = 15.012(3) Å, c = 10.699(2) Å, alpha = 104.76(2) degrees, beta = 102.63(2) degrees, gamma = 99.44(2) degrees, V = 1830.1 Å(3), Z = 2. In compound 6, the coordination geometry around both copper centers resembles a distorted square pyramid, while the stereochemistry around the copper centers in 7 is best described as trigonal bipyramidal. Both complexes display well-resolved isotropically shifted (1)H NMR spectra. Selective substitution studies and integration data have been used to definitively assign several signals to specific ligand protons. Results from the solution (1)H NMR studies suggest that the basal and apical imidazole groups do not exchange rapidly on the NMR time scale and the solid state structures of the complexes are retained in solution. In addition, the magnetochemical characteristics of 6 and 7 were determined and provide evidence for "magnetic orbital switching". Antiferromagnetic coupling in 6 (J = -130 cm(-)(1)) is strong, while the copper centers in compound 7 are ferromagnetically coupled (J = +16.4 cm(-1)). Differences in the magnetic behavior of the two copper centers have been rationalized using the "ligand orbital complementary" concept. The ground state magnetic orbitals involved in spin coupling in 6 (d(x)()()2(-)(y)()()2) are different from those in 7 (d(z)()()2).