Search

A new class of phenalenyl-based neutral radical molecular conductors has recently been reported; a distinctive feature of these molecular solids is the absence of the well-defined conducting pathway(s) that are characteristic of the organic charge- transfer salts. These radicals do not stack in the solid state, and the requisite carbon- carbon contacts are all larger than the sum of the van der Waals distances. Magnetic susceptibility measurements show that these compounds usually exist as isolated free radicals with one spin per molecule (at least over some temperature range), apparently supporting the idea that there is little interaction between the molecules in the solid state. Nevertheless, these radicals show the highest conductivity (RT 0.05 S/cm) of any neutral organic solid and the conduction mechanism is at present unresolved. In this article we report a structurally related radical with a resistivity five orders of magnitude higher than that of the previously reported radicals. We analyze the crystallographic and electronic structure of this solid in detail and point out some of the challenges that remain in relating structure, magnetism, and conductivity in this new class of organic solids. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 95: 853- 865, 2003

Bifunctional 1,2,3-dithiazoles bridged with azine and phenylenediamine spacers have been prepared, with a view to determining the extent of communication between the two dithiazole rings as a function of the electronic and steric demands of the bridge. The crystal structure of the closed-shell diazine derivative [S(2)NClC(2)=NN=C(2)ClNS(2)] is rigorously planar. Cyclic voltammetry on this compound indicates two reversible one-electron oxidations. The radical cation state has been characterized by EPR spectroscopy and by crystal structure determination of its 1:1 PF(6)(-) salt. The latter reveals little interaction between neighboring radical cations; consistently, the material exhibits a conductivity of sigma10(-5) S cm(-1). Insertion of a phenylene group into the diazine bridge to afford [S(2)NClC(2)=NC(6)H(4)N=C(2)ClNS(2)] leads to significant torsional motion between the phenylene ring and the two end groups, as a result of which the two DTA rings are electronically independent; no radical cation state has been observed for this species. Crystal data for Cl(2)S(4)N(4)C(4): a = 5.1469(15), b = 13.343(2), c = 14.2031(17), orthorhombic, Pbca, Z = 4. Crystal data for Cl(2)S(4)N(4)C(4)PF(6): a = 11.699(4), b = 12.753(5), c = 10.461(4), beta = 112.17(1) degrees, monoclinic, C2/c, Z = 4. Crystal data for C(l2)S(4)N(4)C(10)H(4): a = 3.9477(6), b = 23.790(3), c = 7.3769(9), beta =90.793(12) degrees, monoclinic, P2(1)/c, Z = 2.

Monomeric five-coordinate nickel−cysteine complexes were prepared using anionic tris(3,5-disubstituted pyrazolyl)borates (Tp* - and TpPhMe-) and l-cysteine (ethyl ester and amino acid forms). Tp*NiCysEt crystallizes with a single methanol of solvation in the monoclinic space group P21: a = 7.8145(18), b = 24.201(6), c = 7.9925(14) A; β = 117.991(16)°. [Tp*NiCys-][K+] and TpPhMeNiCysEt show magnetic and electronic characteristics similar to Tp*NiCysEt, so that the trigonal bipyramidal coordination geometry confirmed for Tp*NiCysEt in the solid state likely applies to all three. All three complexes have high spin magnetic ground states at room temperature (μeff = 2.9−3.2 μB, S =1). Their electronic spectra are dominated by sulfur to nickel charge-transfer bands (388−430 nm in chloroform) with energies that correlate to respective thiolate basicities and TpX- donor strengths. The Tp* derivatives undergo a rapid reaction with molecular oxygen. Stoichiometric, infrared, and electronic spectroscopy measurement...

The reactions of chlorocyclophosphazenes N3P3Cl6 (1) and N4P4Cl8 (2) and polydichlorophosphazene (3) with cyclohexylamine, cyclopentylamine, and cyclopropylamine have been studied. The major product with 1 is the geminal tetrakis derivative N3P3Cl2(NHR)4, while 2 gives the completely substituted derivative, N4P4(NHR)8. X-ray crystal structure determinations of N3P3Cl2(NHC6H11)4 (1a) and N4P4(NHC3H5)8 (2c) have been carried out. 1a crystallizes in a triclinic space group, P1, with a = 11.2330(13) A, b = 11.4269(16) A, c = 13.4055(12) A, α = 72.211(10)°, β = 72.150(9)°, γ = 81.777(11)°, V = 1557.3(3) A3, and Z = 2. 2c crystallizes in a monclinic space group, P21/n, with a = 12.433(3) A, b = 20.484(4) A, c = 12.645(3) A, β = 92.81(2)°, V = 1557.3(3) A3, and Z = 4. The cycloalkylamino-substituted polyphosphazenes contain a small amount of residual chlorine atoms. These have high glass transition temperatures.

A content analysis looked at 650 Internet mail messages sent to NBC Nightly News in response to an invitation during a series dealing with the impact of new technologies. Message indexes were created to reflect the scope of the audience they addressed. Macro-scopic messages were formal, dealt with political issues, and either did not mention technology or mentioned mass media. These messages resembled a letter to a newspaper editor. Mezzoscopic messages were positive and avoided political issues. They congratulated NBC as a team for their work on the technology series and tended to mention computers. Micro-scopic messages stood out for their authors' high perception of interactivity. These messages mentioned computer technology more than any other group and appear similar to face-to-face communication in many ways. Results are discussed in terms of how the relationship between media users' perceived sense of interactivity and the scope of the audience they address are related to message style and content.

A new organic molecular conductor, based on a spiro-biphenalenyl neutral radical, simultaneously exhibits bistability in three physical channels: electrical, optical, and magnetic. In the paramagnetic state, the unpaired electrons are located in the exterior phenalenyl units of the dimer, whereas in the diamagnetic state the electrons migrate to the interior phenalenyl units and spin pair as a π-dimer. Against all expectations, the conductivity increases by two orders of magnitude in the diamagnetic state, and the band gap decreases. This type of multifunctional material has the potential to be used as the basis for new types of electronic devices, where multiple physical channels are used for writing, reading, and transferring information.

The title molecule, 3,7-bis(2-thienyl)-1,5,2,4,6,8-dithiatetrazocine, C 10 H 6 N 4 S 4 , is planar within 0.069 (5) A and crystallizes in the monoclinic space group P2 1 /c. There are two centrosymmetric molecules in the cell; these are stacked such that each eight-membered C 2 N 4 S 2 ring has a thienyl ring above and below it. The mean interplanar separation is 3.55 (2) A.

The radical units Se 2 N 2 CMe dimerize with long Se...Se distances of 3.159(3) and 3.187(3) A to give the title compound, C 4 H 6 N 4 Se 4 . There are two crystallographically independent dimers in the unit cell. The dimers adopt a twisted conformation with parallel ring planes. One ring is rotated on the axis between ring centers by approximately 90° from the eclipsed position to give Se-Se-Se-Se torsion angles of 86.81(15) and 88.95 (17)°. Se-Se bond lengths within the radicals vary from 2.306 (3) to 2.330 (3) A.

The title compound, [Cu(C 10 H 14 N 4 O 2 P) 2 ], consists of pairs of bis(dimethylpyrazolyl)phosphinato groups coordinated to copper(II) atoms sitting on inversion centers. The compound has Cu-N bond distances of 2.009 (4) and 2.010 (4) A and an N-Cu-N angle of 89.27 (13)° . The phosphinato O atoms weakly coordinate the copper ions with bond distances of 2.490 (3) A.

The title compound [Ru(C 5 H 5 )(C 2 H 5 NS)(C 18 H 15 P) 2 ]BF 4 crystallizes in the space group P2 1 /c. The Ru atom has pseudotetrahedral coordination geometry formed by the cyclopentadienyl centroid, the two PPh 3 ligands and the S atom of the neutral thioacetamide molecule. The Ru-S and C=S distances are 2.3820 (13) and 1.671 (5) A, respectively, and the Ru-S=C angle is 116.3 (2) o . The Ru atom is at a distance of 0.405 (9) A from the plane formed by the atoms of the thioacetamide group

[Fe(CO) 4 (SO 2 )(C 5 H 5 ) 2 ]•H 2 O cristallise dans P2 1 /n avec a=10,884, b=12,424, c=12,658 A, β=103,35 o , Z=4; affinement jusqu'a R=0,0355. Les liaisons hydrogene entre l'eau et SO 2 lient les complexes entre eux. L'eau provoque la cristallisation du complexe dans usne conformation trans, en opposition a la forme gauche du materiau anhydre

[Rh(C 13 H 23 ) {(PCC 6 H 5 ) 3 } 2 ]•0,5 C 6 H 6 cristallise dans P1 avec a=12,260, b=13,05, c=15,91 A, α=71,30, β=76,24, γ=67,71 o , τ=2; affinement jusqu'a R=0,043. Les atomes du cycle a 13 chai←nons sont dans une configuration trans. Les distances des 3 atomes de ce cycle lies au metal sont de 2,120; 2,180; 2,231 A, et les angles formes par ces atomes sont de 123,9 et 125,7 o

C 16 H 22 S 2 cristallise dans P2 1 /n avec a=8,851, b=15,398 et c=11,590 A, Z=4; affinement jusqu'a R=0,036. Presence de quatre contacts intramoleculaires entre les atomes H et le cycle phenylene dans le domaine 2,53 a 2,68 A, contribuent au «benzene courbe» typique des paracyclophanes

The synthesis and crystal structure of 2,5-diamino-3,6-dichloropyrazine, C4H4Cl2N4, are described. The centrosymmetric molecule has an exocyclic C—N distance of 1.362 (3) A, and a nearly planar amine group [the angles at N sum to 351 (2)°]. Within the crystal, the molecules form a ribbon through two centrosymmetric pairs of N—H⋯N hydrogen-bond interactions, where the N⋯N distance is 3.110 (3) A.

A crystallographic twofold rotation axis passes through the C-C bond joining the imidazole rings of the title compound, C10H10N4O2. The molecule crystallizes in a cis disposition. The planar acetyl group is twisted by 5.0 (3)° with respect to the imidazole ring and the two imidazole rings are tilted by 60.53 (5)° in relation to one another.

The title molecules, C 6 H 4 N 6 O 4 .2C 3 H 7 NO, lie on a center of inversion. One N atom of the ring is hydrogen bonded to the O atom of the dimethylformamide (DMF) solvate molecule [N-H...O = 2.699 (4) A]. The nitro group is tilted by 4.11 (18)° with respect to the imidazole ring.

Ru(HSO3)2(NH3)4), Mr=331.3, mono- clinic, P21/c, a = 6.2019 (15), b = 7.0213 (11), c = 11.761 (2)A, fl= 115.30(2) °, V= 463.0 (3) A 3, Z= 2, Dx = 2-38 g cm -3, A(Mo Kte) = 0.71073 A,, /z = 21-0 cm- 1, F(000) = 332, T = 293 K, R = 0.019 for 1179 reflections with Fo 2 > 3o'(Fo2). The complex lies on an inversion center with Ru-N distances of 2.141 (2) A, and a Ru-S distance of 2-2785 (5) A.. All of the H atoms are linked to O atoms of neighboring hydrogensulfite ligands in an extensive network of H bonds. Experimental. The title complex (I) was obtained by the procedure described by Vogt, Katz & Wiberley (1965). Colorless crystals were obtained by slow cooling of the reaction mixture. Data crystal was 0.12 x 0-20 x 0-32 mm and was mounted with epoxy on a glass fiber. Intensities measured with an Enraf- Nonius CAD-4 diffractometer using o~--20 scans of 4-16 ° min-~ in 0. Unit cell determined from least- squares analysis of angle data for 25 reflections with 17 < 20 < 22 °. Analytical absorption correction varied from 0-79 to 1.00. Data collected to (sin0)/A =0.68A.-', 0_

K[RuCl 4 (C 10 H 8 N 2 )] cristallise dans Pbcn avec a=14,382, b=13,980 et c=7,491 A, Z=4; affinement jusqu'a R=0,051. L'anion [Ru(bpy)Cl 4 ] − est sur un axe cristallographique d'ordre 2. Les cycles organiques des anions voisins se recouvrent avec des espacements entre les plans 3,27 et 3,36 A

The cation trans -[Ru(bpy) 2 (PPh 3 ) 2 ] 2+ and trans -[Ru(Me 2 bpy 2 ) 2 (py) 2 ] 2+ both contain bipyridine ligands which are distorted because of the crowding of the two chelate units. The hexafluorophosphate salt of the first cation crystallizers in space group P2 1 /n, with a = 11.630(1), b = 20.245(2), c = 11.299(1)A, &#x03B2 = 103.99(1)°, and Z = 2. R = 0.047 for 2396 observed reflections. The hexafluorophosphate salt of the second cation crystallizers in space group C2/m, with a = 18.392(2), b = 11.265(1), c = 13.383(1)A, &#x03B2 = 139.42(2)°, and Z = 2. R = 0.047 for 1403 observed reflections. The Ru of the first cation lies on an inversion center and the Ru of the second cation lies on a special position of 2/m symmetry. The distortions of a number of bipyridine complexes with the trans geometry are analyzed and found to fall into two categories, bowed or twisted. The two complexes of this report were found to have a bowed conformation.

Phenothiazine-10-propionitrile, C12H8SNC2H4CN, crystallizes in the centrosymmetric monoclinic space group P21/n, with a = 5.785(1)A, b = 15.427(3)A, c = 14.497(4)A, β = 92.50(1)°, Z = 4, Dmeas = 1.29(1) g cm3 and Dcalc = 1.28 g cm3 at 23°. Three dimensional X-ray data were collected with a manual diffractometer using MoKα (λ 0.71069A) radiation and by multiple film Weissenberg techniques using CuKα (λ 1.5418A) radiation. The structure was determined by Patterson and Fourier methods and refined with 519 observed reflections by full matrix least-squares methods to an R of 0.077. The dihedral angle between the two planes of the o-phenylene rings is 135.4(3)°. In the folded heterocyclic ring the C-S-C angle is 97.8(7)° and the average CS bond is 1.76(1)A. A comparison of this structure to that of phenothiazine-10-propionic acid shows the two chemically similar molecules have the same dihedral angles in spite of completely different solid state packing patterns.

The crystal structure of phenothiazine-10-propionic acid, C12H8SNC2H4COOH, was determined from three-dimensional X-ray diffraction data collected with a manual diffractomer using MoKα (λ 0.71069 A) radiation. The space group is P21/c with a = 7.888 (2)A, b = 8.703 (2)A, c = 19.700 (8)A, β = 101.42 (1)°, Z = 4, Dmeas = 1.35(2) g. cm−3 and Dcalc = 1.36 g. cm−3 at 23°. The structure was determined by the direct method and refined with 500 observed reflections by full-matrix least squares to an R of 0.072. The molecule is folded along the S-N axis and the dihedral angle is 136.5°. The C-S-C angle is 98.5(7)° and the average C-S bond is 1.77(2)A. The shortening of the C-S bond, the small value of the C-S-C angle and the folding of the molecule are typical of the phenothiazine class of compounds and are assumed to be due to sulfur d orbital participation in ring bonding.

Cu(C 7H9N)(C 12H8N2)2 ) (CIO4)2, M r = 730.0, monoclinic, P2,/n, a = 18.430 (3), b = 9.122(2), c=18.744(8)A, fl=97.92(3) °, V= 3121 (3) A 3, z = 4, Dm = 1.56 (1), D x = 1.55 gcm -3, 2(Mo Ka) = 0.71073 A, g = 9.3 cm -l, F(000) = 1492, T=293K, R=0.081 for 1312 unique observed reflections. The Cu-atom environment is approxi- mately square pyramidal, with the apical position occupied by an N atom of a 1,10-phenanthroline (phen) molecule. The Cu atom is 0.256 (3)A above the basal

P 3 (C 6 H 5 ) 6 N 4 H 2 + •Cl − •H 2 O cristallise dans le systeme monoclinique avec le groupe d'espace P2 1 /n. Affinement de la structure jusqu'a 0,047

The structure of 2-(trifluoromethyl)phenothiazine, C13H8NSF3, was determined by single crystal X-ray diffraction. The molecule crystallizes in space group P212121, with a = 7.766(2), b = 5.957(1), and c = 23.499(5)A. The final R value is 0.073. The CSC bond angle is 102.0°, the CNC bond angle is 124.8°, and the dihedral angle between the phenylene planes is 171.2(1)°. The hydrogen atom bonded to the nitrogen atom was located; it is on the inside of the butterfly angle and the S…NH bond angle is 173.3°.

C 14 H 11 N 3 OS cristallise dans le systeme orthorhombique avec le groupe d'espace Pbca. Affinement de la structure jusqu'a 0,044. La portion N 3 C 2 du cycle est plane

[Cu(C 7 H 9 N) 2 (C 12 H 8 N 2 )(CH 2 O)] (ClO 4 ) 2 cristallise dans le systeme triclinique avec le groupe d'espace P1. Affinement de la structure jusqu'a 0,040. La coordination autour de Cu est pyramidale carree

Na 4 [Ru(SO 3 ) 2 (HSO 3 ) 2 (NH 3 ) 2 ]•6H 2 O cristallise dans le systeme monoclinique avec le groupe d'espace P2 1 /c. Affinement de la structure jusqu'a 0,044. Le complexe anionique centrosymetrique et pseudo-octaedrique

C7HsC12N3S2, Mr=266.17, triclinic, P), a=6-028(1), b=9-985(2), c=10.157 (3) /~, ct= 117.33 (2), fl= 106.73(2), y=90.31(1) °, V= 513-3(4)/~3, Z=2, D x=1.72gcm -3, 2(MoK~t)= 0.71073 A, /1 = 9.85 cm -1, F(000) = 268, T= 293 K, R = 0.032 for 1547 unique observed reflections. The SNCNS portion of the ring is planar within 0-060 (2)/~ and the third N is displaced 0.336 (2) A from this plane on the side opposite the S-bonded C1 atoms. The S-N distances range from 1.581 (1) to 1.615 (2)/~ and the N-C distances are 1.327 (2) and 1.344 (2) ./k. Experimental. Compound prepared by the reaction of chlorine gas with PhCNsS 3 obtained from the reaction of PhC(NSiMe3) with SaNaC1 a. Crystals obtained from a 50:50 mixture of dichloromethane and hexanes. Air-sensitive parallelpiped data crystal 0.20 × 0.50 × 0.46 mm sealed in a glass capillary. Density not measured. Intensities measured with an Enraf-Nonius CAD-4 diffractometer using 09-20 scans of 4 to 16 ° min -~ in 0. Unit cell determined from least-squares analysis of angle data for 20 reflections with 22 < 20 < 40 °. Analytical absorption correction based on crystal shape varied from 0.67 to 1-00. Data collected to sin0/2 of 0-59/~-~, -7

A one‐film method for orienting single crystals using an oscillation film obtained with a Weissenberg camera is described. Highly precise orientation corrections are obtained by using the curvature of the nonzero lines, which is more sensitive to crystal orientation than the zero layer line curvature used in other methods. The equations used for the corrections are derived, rather than empirical, and a general equation for the shapes of the lines caused by a misoriented crystal is given.