Octahedral Anions Research Articles

Synthesis and properties of alkyl-substituted DTEDT derivatives

Several derivatives of alkyl-substituted DTEDT have been synthesized. Single crystals of cation radical salts of dimethyl-DTEDT ( 1Ab) with octahedral anions showed high conductivities ( σ rt = 10 0–10 1 Scm −1) and metal-like behavior around room temperature. The metal to insulator transition temperature tends to decrease as the volume of anions increases. The PF 6, AsF 6 salts of cyclopenteno-DTEDT ( 1Ac), and TaF 6 salt of tetramethyl-DTEDT ( 1Bb) show metallic conducting behavior down to 50 K.

A Mixed Cation Ternary Nitroprusside: [(CH3)4N][Na][Fe(CN)5(NO)].2.5H2O

The title compound,sodium tetramethylammonium pentacyano(nitrosyl)ferrate(II) 2.5-hydrate, is a ternary nitroprusside with an asymmetric unit composed of an octahedral nitroprusside anion, a disordered tetrahedral tetramethylammonium cation, a sodium cation and 2.5 water solvate molecules.

Bis(1,3-dithiole-2-thione-4,5- dithiolato)diarylantimonate(1-)], [Ar 2Sb(dmit) 2] −, complexes. Crystal structures of [NEt 4][Ar 2Sb(dmit) 2] (Ar = Ph or p-tolyl)

The ionic complexes [Q][Ph 2Sb(dmit) 2] ( 4; Q = NEt 4 or 1,4-Me 2-pyridinium) and [Net 4][( p-tolyl) 2Sb(dmit) 2] ( 5) have been prepared from [Q] 2Zn(dmit) 2] and Ar 2SbCl 3 in the presence of KSCN (H 2-dmit = 4,5-dimercapto-1,3-dithiole-2-thione). As shown by X-ray crystallography for 4 (Q = NEt 4) and 5, these complexes contain distorted octahedral anions with cis-aryl groups: The CSbC angles in 4 (Q = NEt 4) and 5 are 93.1(2) adn 95.3(5)°, respectively. The dmit chealtes are unsymmetrically bonded to antimony in both 4 (Q = NEt 4) and 5 with the longer bonds trans to the aryl groups (for both compounds, the SbS bond lengths are in the ranges, 2.614 to 2.636 and 2.530–2.550 Å).

Phase transitions in new BEDT-TTF κ-phase salts with hexacyanometalate anions [M(CN) 63− M=Co(III) and Fe(III)

The preparation, crystal structure determination and physical properties of the compounds formulated as κ-(BEDT-TTF) 4((C 2H 5) 4N)M(CN) 6.3H 2O (M= Co III and Fe III) are presented. Organic ET layers with packing of orthogonalized dimers containing charge carriers and inorganic octahedral hexacyanometalate anions with diamagnetic or paramagnetic transition metals coexist in the title compounds. Two phase transitions occuring respectively at 150 K and in the 230–260 K range have been evidenced by magnetic (SQUID and ESR), DSC measurements. However, preliminary X-Ray studies revealed a structural change around 240 K only.

Complexes Containing cis-[MoVO2]+ and cis-[MoVO(OH)]2+ Centers

Cobaltocene reduction of LMoVIO2(SPh) complexes yielded extremely dioxygen-sensitive cobaltocenium salts of the cis-dioxo-Mo(V) radical anions cis-[LMoVO2(SPh)]-, while sodium acenaphthalenide reduction of LaMoVIO2(SPh) yielded a complex sodium salt containing [LaMoVO2(SPh)]- [L = hydrotris(3,5-dimethylpyrazol-1-yl)borate (La), hydrotris(3-isopropylpyrazol-1-yl)borate (Lb), or hydrotris(3,5-dimethyl-1,2,4-triazol-1-yl)borate (Lc)]. Crystals of [CoCp2][LcMoVO2(SPh)]·toluene were orthorhombic, space group Pbca, with a = 17.695(3) Å, b = 19.490(3) Å, c = 21.925(4) Å, V = 7561(2) Å3 for Z = 8. The structure, refined using a full-matrix least-squares procedure and 2269 data, converged with R = 0.067 (Rw = 0.067). In the distorted octahedral anion, the metrical parameters of the cis-MoVO2 fragment [Mo−O = 1.742(9) Å, O−Mo−O = 112.1(4)°] are significantly larger than those of LcMoVIO2(SPh) [average Mo−O = 1.700(6) Å, O−Mo−O = 103.9(2)°]. 18O-Substitution of [CoCp2][La,bMoVO2(SPh)] permitted the assignment of bands at ca. 870 and 770 cm-1 to the νs and νas modes, respectively, of the cis-MoVO2 fragment. Freshly prepared solutions of [CoCp2][LMoVO2(SPh)] exhibited a broad EPR signal (g, 1.92; W1/2, 20 G) characteristic of a cis-[MoVO2]+ complex. The signal was stable when L = Lc but when L = La or Lb it was replaced by a proton-coupled signal characteristic of a cis-[MoVO(OH)]2+ center. The complex LaMoVO(OH)(SPh) was isolated as a coprecipitate with its conjugate base salt [CoCp2][LaMoVO2(SPh)]. It was characterized by infrared bands at 915 and 535 cm-1, assigned to ν(MoO) and ν(MoOH) modes, respectively. The anions were readily converted to air-stable LMoVO(OSiMe3)(SPh) upon reaction with Me3SiCl and reacted with dioxygen to regenerate LMoVIO2(SPh). The paper reports the first isolation in substance of compounds containing novel cis-[MoVO2]+ and cis-[MoVO(OH)]2+ centers and the first crystallographic characterization of a cis-dioxo-Mo(V) species.

Carbonyl-molybdenum complexes of the hydrotris(3,5-dimethyl-1,2,4-triazol-1-yl) borate ligand

The reaction of KBH 4 with 3 equiv. of 3,5-dimethyl-1,2,4-triazole at ca. 230°C yielded potassium hydrotris(3,5-dimethyl-1,2,4-triazol-1-yl) borate, K{HB(Me 2tz) 3}. The reaction of Mo(CO) 6 and K{HB(Me 2tz) 3} in N, N-dimethylformamide at 110°C gave [{HB(Me 2tz) 3}Mo(CO) 3] −, which was isolated as the salt NEt 4[{HB(Me 2tz) 3}Mo(CO) 3] ( 1). Crystal characterisation of 1 revealed a six-coordinate, distorted octahedral anion composed of a facial, tridentate HB(Me 2tz) 3 − ligand and three mutually cis (facial) carbonyl ligands. Spectroscopic data were consistent with greater electron-withdrawal by the triazolyborate ligand than by the related hydrotris(3,5-dimethylpyrazol-1-yl)borate ligand. Reaction of 1 with iodine gave {HB(Me 2tz) 3}Mo(CO) 3I, which was spectroscopi characterised as a seven-coordinate 3:3:1 face-capped octahedral complex.

Group 9 Chalcogenometalates.

The compounds [K(18-crown-6)](3)[Ir(Se(4))(3)] (1), [K(2.2.2-cryptand)](3)[Ir(Se(4))(3)].C(6)H(5)CH(3) (2), and [K(18-crown-6)(DMF)(2)][Ir(NCCH(3))(2)(Se(4))(2)] (3) (DMF = dimethylformamide) have been prepared from the reaction of [Ir(NCCH(3))(2)(COE)(2)][BF(4)] (COE = cyclooctene) with polyselenide anions in acetonitrile/DMF. Analogous reactions utilizing [Rh(NCCH(3))(2)(COE)(2)][BF(4)] as a Rh source produce homologues of the Ir complexes; these have been characterized by (77)Se NMR spectroscopy. [NH(4)](3)[Ir(S(6))(3)].H(2)O.0.5CH(3)CH(2)OH (4) has been synthesized from the reaction of IrCl(3).nH(2)O with aqueous (NH(4))(2)S(m)(). In the structure of [K(18-crown-6)](3)[Ir(Se(4))(3)] (1) the Ir(III) center is chelated by three Se(4)(2)(-) ligands to form a distorted octahedral anion. The structure contains a disordered racemate of the Deltalambdalambdalambda and Lambdadeltadeltadelta conformers. The K(+) cations are pulled out of the planes of the crowns and interact with Se atoms of the [Ir(Se(4))(3)](3)(-) anion. [K(2.2.2-cryptand)](3)[Ir(Se(4))(3)].C(6)H(5)CH(3) (2) possesses no short K.Se interactions; here the [Ir(Se(4))(3)](3)(-) anion crystallizes as the Deltalambdalambdadelta/Lambdadeltadeltalambda racemate. In the crystal structure of [K(18-crown-6)(DMF)(2)][Ir(NCCH(3))(2)(Se(4))(2)] (3), the K(+) cation is coordinated by an 18-crown-6 ligand and two DMF molecules and the anion comprises an octahedral Ir(III) center bound by two chelating Se(4)(2)(-) chains and two trans acetonitrile groups. The [Ir(Se(4))(3)](3)(-) and [Rh(Se(4))(3)](3)(-) anions undergo conformational transformations as a function of temperature, as observed by (77)Se NMR spectroscopy. The thermodynamics of these transformations are: [Ir(Se(4))(3)](3)(-), DeltaH = 2.5(5) kcal mol(-)(1), DeltaS = 11.5(2.2) eu; [Rh(Se(4))(3)](3)(-), DeltaH = 5.2(7) kcal mol(-)(1), DeltaS = 24.7(3.0) eu.

Structures and Conducting Properties of CPTM-TTP Salts

Abstract The title donor, CPTM-TTP (4,5-cyclopenteno-4′,5′-bis-(methylthio)-2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapen-talene) has produced metallic cation radical salts with octahedral and linear anions. Among them, (CPTM-TTP)4AsF6 has a two-dimensional “β-type” arrangement of donor molecules and a closed Fermi surface.

Two Anionic Indium(III)–Thiocyanate Complexes with Potassium-Centred Complex Cations

Crystallization of the product of the reaction between impure samples of In(NCS) 3 , prepared from InCl 3 and KSCN, and 2,2'-bipyridyl (bipy) in tetrahydrofuran solution gave the complex pentakis(tetrahydrofuran)potassium (2,2'-bipyridyl)tetrakis(isothiocyanato)indate(III), [K(C 4 H 8 O) 5 ][In(NCS) 4 (C 10 H 8 N 2 )], composed of a potassium cation coordinated by five thf ligands and one S atom of a thiocyanate group, and an octahedral indium-centred anion in which the bipy N atoms are cis and the four thiocyanates are bonded to indium through their N atoms. Crystallization of samples of impure In(NCS) 3 from pyridine in the presence of 18-crown-6 gave the compound (1,4,7,10,13,16-hexaoxacyclooctadecane)potassium bis(pyridine)tetrakis(isothiocyanato)indate(III) pyridine solvate, [K(C 12 H 24 O 6 )][In(NCS) 4 (C 5 H 5 N) 2 ].2C 5 H 5 N, containing an octahedral indium-centred anion in which the pyridine ligands are trans. The potassium in both complexes arises from the contamination of In(NCS) 3 by the KSCN used in its preparation.

Syntheses and crystal structures of the ruthenium carbidocarbonyl clusters [Ru5C(CO)11(µ-Br)2(η3-C3H5)(µ-η3-C3H5)], [Ru5C(CO)13I(µ-I)(µ-η2-COMe)]–, [Ru5C(CO)14(µ-Br)2] and [Ru6C(CO)16(µ-Br)]–with novel metal frameworks

The reaction of the octahedral cluster anion [N(PPh3)2][Ru6C(CO)15(µ-η3-C3H5)] with allyl bromide at 115 °C afforded the pentanuclear cluster [Ru5C(CO)11(µ-Br)2(η3-C3H5)(µ-η3-C3H5)] containing a square-based pyramidal geometry in which two adjacent apical-to-basal edges are cleaved and replaced by two symmetrically bridging Br atoms. One allyl ligand bridges a Ru–Ru edge of the square base in a µ-η3 fashion, while the other allyl group co-ordinates to the apical Ru atom as a simple η3 ligand. The reaction of the octahedral cluster anion [N(PPh3)2][Ru6C(CO)16(Me)] with methyl iodide in CH2Cl2 at 150°C gave the cluster [N(PPh3)2][Ru5C(CO)13I(µ-I)(µ-η-2-COMe)] displaying a square-based pyramidal geometry in which two opposite apical-to-basal edges are cleaved and bridged by a µ-η2 acetyl group and an I atom. The complex [N(PPh3)2]2[Ru6C(CO)16] reacted with benzyl bromide at 60 °C to give the novel octahedral cluster [N(PPh3)2][Ru6C(CO)16(µ-Br)] in which one edge of the metal framework is cleaved and symmetrically bridged by a Br atom. Further reaction with benzyl bromide at 130 °C led to [Ru5C(CO)14(µ-Br)2], which exhibits the same metal geometry as the iodide with two Br atoms symmetrically bridging two opposite apical-to-basal edges of the square-based pyramidal geometry.

Chemistry of the carbido- and nitrido-decaruthenium cluster anions [Ru10H(C)(CO)24]–, [Ru10C(CO)24]2–and [Ru10N(CO)24]–

The thermolysis of [Ru3(CO)12]1 in the presence of 1,3,5-trimethylbenzene yielded, in addition to hexaruthenium carbido products, the tetracapped octahedral carbido cluster anion [Ru10H(C)(CO)24]–2 which has been fully characterised as its [N(PPh3)2]+ salt. Deprotonation of 2 yielded the dianion [Ru10C(CO)24]2–3 which has been similarly characterised. The isostructural decaruthenium nitrido anion [Ru10N(CO)24]–4 may be synthesised by condensation of the required stoichiometric quantities of [Ru3(CO)12] with the preformed nitrides [Ru5N(CO)14]– or [Ru6N(CO)16]– under thermolysis in bis(2-methoxyethyl) ether (diglyme), or alternatively directly from [Ru3(CO)12] by reaction with 1/3 equivalent of [N(PPh3)2][N3] under the same conditions. The anion 4 as its [N(PPh3)2]+ salt forms crystals isomorphous to those of 2, and conclusive evidence for its containing an interstitial nitride was therefore obtained by observation of its 14N NMR resonance at δ 30 [δ(14N, MeNO2)= 0]. Reaction of 3 with 1 atm CO in solution leads to rapid degradation to [Ru6C(CO)16]2– and [Ru3(CO)12] whilst under the same conditions 4 yields [Ru5N(CO)14]– and [Ru3(CO)12].

Dipyridiniomethane chloropentafluoroosmate(IV), [(C5H5N)2CH2][OsF5Cl

The sublattice of the mixed-ligand complex anions, [OsF 5 Cl] 2− , of the title compound [N,Nmethylenepyridinium chloropentafluoroosmate(IV)] is completely ordered. Due to the mutual trans influence in the asymmetric Cl-Os-F axis, the Os-F distance of 1.959 (4) A is slightly longer in comparison to the average value of 1.919 A found for the symmetric F-Os-F axes. Accordingly, the Os-Cl distance of 2.3329 (2) A is shortened in relation to that of 2.364 A in the octahedral complex anion of K 2 [OsCl 6 ]

Lattice stability in A2MCl6 ionic crystals (A identical to C5H5NH or CH3C5H4NH; M identical to Sn or Te)

DSC and NQR measurements were carried out for (CH3C5H4NH)2SnCl6 and (CH3C5H4NH)2TeCl6. No structural phase transition was observed above 85 K and 130 K up to the melting points for the Sn and Te compounds, respectively. Many A21MCl6 ionic crystals, where (MCl6)2- is an octahedral anion such as (SnCl6)2- or (TeCl6)2-, exhibit structural phase transitions accompanied by rotations of the MCl6 octahedra. However, (C5H5NH)2SnCl6 and (C5H5NH)2TeCl6 have been reported not to show such a displacive phase transition between 77 K and the decomposition temperature, although they undergo phase transitions driven by ordering of the pyridinium cations C5H5NH+. The stable lattices in these four compounds are discussed and explained qualitatively in terms of N-H...Cl hydrogen-bonding networks and a large primitive-cell volume.

Dipyridiniomethane cis-dichlorotetrafluoroosmate(IV)

The structure of dipyridiniomethane cis-dichlorotetrafluoroosmate(IV) {or N,N-methylenedipyridinium dichlorotetrafluoroosmate(IV), cis-[(C 5 H 5 N) 2 CH 2 ][OsF 4 Cl 2 ]}, has been determined by single-crystal X-ray diffraction at room temperature. The complex anions are completely ordered in the lattice. As a result of the trans influence in the two asymmetric axes Cl-Os-F, the Os-F distances of 1.941 (4) and 1.953 (5) A are slightly lengthened compared to those of the symmetric F-Os-F axis of 1.931 (5) and 1.934 (4) A. Correspondingly, the Os-Cl distances of 2.324 (2) and 2.335 (2) A are shortened in comparison with those of 2.364 A in the octahedral complex anion of K 2 [OsCl 6 ]

Vertical Electron Detachment Energies for Octahedral Closed-Shell Multiply-Charged Anions

The local stability of several octahedral species AlFs3-, GaFa3-, InF6>, TlF&, TaF6-, ZrFb, LaF6>, and LaCls3- was studied by using ab initio methods. All systems were found to have minima at octahedral geometries. The electronic stability of these species was considered by using electron propagator theory (EFT) and the Mraller-Plesset (MP) perturbation scheme. The results indicate that triply-charged molecular species may be electronically stable in the gas phase. Due to the slow convergence of the EFT and MP series and limitation in our one-electron basis set, the final conclusion requires a more advanced theoretical treatment. The doubly- (ZrFa2-) and singly-charged (TaFa-) species were found to possess very high electronic detachment energies of 5.0 and 10.6 eV, respectively. TaF6- is predicted to be thermodynamically stable and ZrF62- slightly unstable with respect to the unimolecular decomposition ML6- -+ MLs('+l)- + L-. I. Introduction Multiply-charged anions are challenging species from the point of view of electronic structure theory. Coulomb repulsion between excess negative charges has to be counterbalanced by an advantageous distribution of the total charge to make the system electronically and geometrically stable. The multiply-charged systems are usually thermodynamically unstable, but if their lifetimes are long enough, they may be considered as promising candidates for high energy density materials.' The discovery of the dianion of benzol(ccilpyrene-6-one by Dougherty2 opened the field of doubly-charged molecular species in the gas phase. An excellent review of the subject from both an experimental and theoretical prespective has recently been published by Compton.3 Briefly, Leiter et al. found doubly- charged anions of the oxygen clusters (02)n2-.4 Schauer et al.

Fluorine magnetic shielding parameters in the [TiF6]2− octahedral anion

Magnetic shielding tensors of fluorine nuclei in the [TiF6]2− octahedral anion were measured by19F NMR. Representative experimental data show them to be independent of the crystal environment of the anion.

Chemistry of iridium carbonyl cluster complexes. Synthesis, characterization and solid state structure of the phosphido carbonyl cluster [Ir6(CO)12(μ-CO)2(μ-PPh2)−

The phosphido-bridged cluster [Ir6(CO)14 PPh2]− has been obtained by reaction of [Ir6(CO)15]2− with PHPh2, in the presence of ferrocenium cation, followed by deprotonation. The anion was isolated as a salt of [N(PPh3)2]+ or K+ and its structure was determined by single crystal X-ray data analysis. The salt [N(PPh3)2][Ir6(CO)14PPh2] crystallizes in the triclinic space group P $$\bar 1$$ witha = 11.835(1) A,b = 15.007(1) A,c = 18.766(2)_ A; α = 78.779(7)°,β = 87.260(8)°,γ = 75.794(6)°,V = 3169.3(7) A,Z = 2. The structure was solved by Direct Methods and Difference Fourier techniques and refined down toR andR w values of 0.034 and 0.036, respectively, for 8003 observed reflections havingl > 3σ(I). The octahedral anion, of idealized C2 symmetry, possesses two distance Ir-P = 2.284 A, formally acting as a three electron donor. Average bond distances (A) and angles (degrees) are: Ir-Ir = 2.776, Ir-C t = 1.87, Ir-C b = 2.05, C t -O t = 1.14, C b -Ob= 1.17, Ir-P-Ir = 74.3°, Ir-C t -O t = 177°, Ir-C b -O b = 138°, Ir-C b -Ir = 84° (t = terminal,b = bridging).

Me3PhN]2[WCl6] und [PPh4]2[W2Cl6O2(μ-N)(μ-Cl2PO2)], ein μ-N-Nitridowolframat mit Dichlorophosphatbrücke

Trimethylphenylammonium hexachlorotungstate(IV), [C 9 H 14 N] 2 [WCl 6 ], consists of octahedral anions that alternate with the cations in layers parallel to (100). In bis(tetraphenylphosphonium) μ-dichlorophosphinato-O:O'-μ-nitrido-bis[trichloro(oxo)tungstate], [C 24 H 20 P] 2 [W 2 Cl 6 O 2 (μ-N)(μ-Cl 2 PO 2 )], the anion contains two W atoms linked symmetrically by an N atom, forming a slightly bent W=N=W group with short bonds; in addition, the W atoms are bridged by a dichlorophosphate group, resulting in a six-membered ring

Structure and Physical Properties of (TMEO-TTP)2Au(CN)2

Abstract Radical cation salts of TMEO-TTP with linear and octahedral anions exhibit metallic conductivity down to 0.6 K. The title salt has two-dimensional donor arrangement, and the measurements of electrical conductivity, thermoelectric power, and ESR show a characteristic metal-to-metal transition.

Crystal Structure and Magnetic Study of a New Iron (III) Phosphate, Fe1.21PO4X (X = F, OH, H2O), Isostructural with 3MgSO4, Mg(OH)2, H2O

Fe3+1.21PO4X (X = F-, OH-, H2O), obtained by hydrothermal synthesis (200°C, 6 days) from a 1:1:2:40 mixture of Fe(NO3)3(H2O)9, P2O5, NH4F, H2O, is tetragonal (S.G. = I41/amd (No. 141)), a = 5.184(1) Å, c = 13.040(5) Å, V = 350.4(3) Å3, Z = 4. Its structure, isotypic with those of Lipscombite, Fe2-δPO4(OH), and 3MgSO4, Mg(OH)2, H2O, is built up from the interconnection of chains of face sharing anionic octahedra (5 × 14 Å2 structure type). The partial occupancy, close to 23, of these octahedra by Fe3+ is discussed. Antiferromagnetism (TN = 81 K) of Fe1.21PO4X was characterized by susceptibility measurements and Mössbauer spectroscopy. The magnetic behavior is analyzed in relation with the two types of disorder (vacancies and nature of X) occuring in the chains.