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We report the crystal structure of a spiro-bis(1,9-disubstituted-phenalenyl)boron cation ( 2 + ) and by comparison with the structures of a series of radicals we conclude that the changes in bond lengths in the radicals compared to those of the corresponding cation can be qualitatively predicted by the sign of the partial bond order of the singly occupied molecular orbital (SOMO), which contains the additional electron. By use of this information, we can analyse the structures of the π-dimer radicals 1 and 2 and ascertain the location of the unpaired electron in these compounds. Where these radicals exist as paramagnetic π-dimers (high-temperature regime), the unpaired electrons reside mainly in the phenalenyl units not directly involved in the π-dimer interaction. At low temperatures, where the diamagnetic π-dimers exist, the electrons localise in the phenalenyl units directly involved in the π-dimer, but there still exists some degree of delocalisation of the electrons to the other halves of the molecules. We postulate that the increase in delocalisation of the unpaired electrons is related to the increase of the conductivity by about two orders of magnitude as the electrons spin pair.

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

The passage of a current through a solid requires a pathway for the movement of electrons or holes. 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 any obvious conducting pathway(s). 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 the first compound to be isolated behaves as a free radical with one spin per molecule, apparently supporting the idea that there is little interaction between the molecules in the solid state. Nevertheless, this radical shows the highest conductivity (σRT = 0.05 S/cm), of any neutral organic solid, and the conduction mechanism is presently unresolved. In the present study, we report a structurally related radical with a resistivity 4 orders of magnitude higher than that of the previously reported radicals. We analyze th...

Dissolution of [CpRu(PPh 3 )(SC 4 H 8 ) 2 ]CF 3 SO 3 in thietane/CH 2 Cl 2 with stirring yields the title compound [CpRu(PPh 3 )(SC 3 H 6 ) 2 ]CF 3 SO 3 ( I ). The single crystal X-ray structure shows a disparity in the puckering of the two thietanes. One thietane ligand is near-planar, with torsion angles of ±1.5(5)° for CSCC and ±1.8(4)° for CCCS; the second thietane ligand of I has torsion angles of ±21.0(4)° for CSCC and ±25.0(3)° for CCCS. Compound I contains both the largest and the smallest torsion angles for any complex reported. Theoretical calculations were carried out for both thietane and for I using the gamess and gaussian 98 packages.

The synthesis and solid-state characterization of the heterocyclic π-radical 1,2,5-thiadiazolo[3,4-b]-1,2,3-dithiazolo[3,4-b]pyrazin-2-yl, 1,2,3-TDTA, is described. The ESR spectrum of 1,2,3-TDTA (in CH2Cl2, 293 K, g = 2.009) confirms a highly delocalized spin distribution, with observable hyperfine coupling to all five nitrogen atoms of the tricyclic molecule (aN = 0.514, 0.343, 0.109, 0.051, and 0.045 mT). While chemical and electrochemical oxidation (E1/2(ox) = 1.14 V vs SCE) of 1,2,3-TDTA requires relatively harsh conditions, reduction is extremely facile (E1/2(red) = 0.15 V vs SCE). More importantly both the observed cell potential Ecell and computed (MNDO) gas-phase enthalpy ΔHdisp for the disproportionation of this and other 1,2,3-dithiazolyls are significantly lower than those observed for their 1,3,2-isomers. Crystals of 1,2,3-TDTA are monoclinic P21/n, with a = 6.6749(16) A, b = 11.7178(14) A, c = 8.6148(14) A, β = 103.297(16)°, and Z = 4. The crystal structure consists of slipped stacks of head...

The structure of 4,4'-bipyridinium diiodide has been determined. The diprotonated cation possesses crystallographic inversion symmetry with the pyridyl rings coplanar. The crystal packing is dominated by weak but directional N-H···I (N···I distance of 3.47(2) A) and C-H···I (C···I distances of 3.74(3)3.77(3) A) interactions to give layers of ions. The layers stack parallel to the (101) direction and are linked together by an additional C-H···I interaction (C···I distance of 3.816(5) A). Crystal data: triclinic, P-1 (No. 2), a = 8.2940(13), b = 8.3842(11), c = 5.0978(8) A, a = 93.761(11)°, s = 112.281(12)°, ? = 106.887(11)°, V = 307.63(8) A3, Z = 1, Scalc = 2.22 g/cm3. Final residual values based on 997 observed (I > 2s(I)) reflections: R = 0.026, Rw = 0.034.

Cosublimation of 2,5-furanbis(1,2,3,5-dithiadiazolyl) [F-2,5-S] and iodine affords 1:1 and 2:1 charge-transfer salts, [F-2,5-S][I] and [F-2,5-S]2[I]. Cosublimation of 2,6-pyridinebis(1,2,3,5-dithiadiazolyl) [P-2,6-S] and iodine affords uniquely the 2:1 charge-transfer salt [P-2,6-S]2[I]. Crystals of the latter belong to the space group P21/c, a = 3.434(3), b = 9.8914(9), c = 30.803(4) A, β = 91.52(3)°, V = 1045.9(9) A3, Z = 2. The structure consists of [P-2,6-S] molecules stacked along the x direction. Pairs of stacks are linked head-on through iodine atoms, which themselves form disordered stacks running parallel to x. The internal structural parameters of the two CN2S2 rings within each molecule suggest that one (linked to iodine) is formally uncharged, while the other is partially oxidized. This latter ring is heavily coordinated through S- - -N linkages to neighboring CN2S2 rings and pyridine. Magnetic susceptibility measurements on [P-2,6-S]2[I] indicate that it is diamagnetic below 220 K.

The structure of the [CpRu(PPh3)2(C6H11SH)]BF4·CH2Cl2 complex was determined by X-ray diffraction techniques; triclinic space group $$P\bar 1$$ ,a=12.567(1),b=13.409(1),c=14.733(1) A, α=95.380(7), β=111.041(7), γ=96.454(8)°,V=2278.5(4) A3,Z=2,R=0.056,R w=0.088. The Ru is attached to two triphenylphosphine ligands, a cyclopentadienyl and the S atom of the cyclohexylthiol. The Ru−S distance is 2.389(2) A and the S−H distance is 1.23 A.

The isolation and characterization of the trimethylenesulfide-coordinated complex, [CpRu(PPh3)2(SC3H6)]CF3SO3, is reported. The structure of [CpRu(PPh3)2(SC3H6)]CF3SO3 was determined by X-ray diffraction techniques: monoclinic space group I2/a, a=23.864(10), b=14.233(3), c=24.385(7) A, β=97.10(3)°, Z=8, R=0.046, Rw=0.065. The Ru is attached to two triphenylphosphine ligands, a cyclopentadienyl and the trimethylenesulfide. The Ru-S distance is 2.3459(20) A.

4-CF3—C6H4—CN3S2, 1, forms symmetrical sulfur-bound adducts with norbornene (NBE), norbornadiene (NBD), and 1-heptene (C7H14), which were studied by 1H, 13C, COSY-45, and HETCORR NMR. 1•NBE exists in solution in a single isomeric form which corresponds to that found in the solid state for 4-CH3O—C6H4—CN3S2•NBE by single-crystal X-ray diffraction: orthorhombic, P212121 with Z = 4, a = 10.224(3), b = 10.369(5), c = 14.075(5). R = 0.0475 and Rw = 0.0492 for 634 data. 1•NBD exists in solution in two isomeric forms which are not interchangeable. One of these corresponds to that found in the NBE adduct, i.e. exo addition; the other is the first example of endo addition. Two bis adducts of stoichiometry NBD•21 have been prepared and separated. They are isomers exhibiting exo-exo and exo-endo addition. The structure of the latter was confirmed by X-ray diffraction: orthorhombic, Pcab with Z = 8, a = 7.816(2), b = 17.264(3), c = 36.842(5). R = 0.068 and Rw = 0.106 for 1506 data. 1•C7H14 exists as a mixture of syn and anti isomers. NMR structure parameters derived here have been applied to published data on over 15 thiazene NBE and NBD adducts.

The reactions of hexakis(3,5-dimethylpyrazolyl)cyclotriphosphazene, N 3 P 3 (3,5-Me 2 Pz) 6 (HPCTP) (3), with copper-(II) halides afford mononuclear HPCTP.CuX 2 (X=Cl, 3a; X=Br, 3b) and dinuclear HPCTP.2CuX 2 (X=Cl, 3c; X=Br, 3d) coordination complexes. Optical absorption spectra and ESR spectra of these complexes; the structure or HPCTP-CuCl 2 was determined by X-ray crystallography.

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 preparation and solid-state characterization of the dimers of the cyanophenyl-substituted 1,2,3,5-dithia- and 1,2,3,5-diselenadiazolyl radicals [NCC6H4CN2E2]· (E = S, Se) are described. Crystals of the 4-cyanophenyl derivatives 4 are triclinic, space group P¯1. The radicals dimerize in a cofacial fashion, with mean intradimer E- - -E spacings of 3.104/3.233 Å (E = S/Se). The dimer units form ribbonlike arrays connected by head-to-tail CN- - -E contacts. The ribbons are packed in an antiparallel fashion with no close interdimer E- - -E contacts. The 3-cyanophenyl sulfur derivative 5 crystallizes in two phases. The α-phase, along with the isomorphous selenium compound, belongs to the monoclinic space group P21/n. As in the 4-cyano derivatives, the radicals dimerize cofacially, generating ribbons connected by head-to-tail CN- - -E contacts. The ribbons, however, are layered with CN2E2 rings oriented into stacks parallel to the a axis. In addition to short intradimer E- - -E contacts (mean values = 3.13 (2)/3.27 (4) Å for E = S/Se), there are relatively short interdimer E- - -E contacts (mean values = 4.26 (5)/4.15 (5) Å (E = S/Se) along the stacking axis. The β-phase of the 3-cyanophenyl sulfur compound 5, monoclinic space group P21/n, forms discrete dimers associated in a trans antarafacial fashion, with intradimer S- - -S contacts of 3.121 (1) Å; there are no close interdimer S- - -S contacts. The 2-cyanophenyl selenium derivative 6 crystallizes in the polar space group P21. In this structure also the dimer units are laced together by short CN- - -Se contacts. The dimers form stacks parallel to the b axis, with mean intradimer and interdimer Se- - -Se contacts of 3.312/4.083 Å, respectively. Lattice constants for the six structures are: 4 (E = S), C8H4N3S2, a = 10.466 (3) Å, b = 10.342 (2) Å, c = 9.169 (2) Å, α = 104.97 (2)°, β = 112.97 (2)°, γ = 69.84 (2)°, V = 849.0 (3) Å3, Z = 4; 4 (E = Se), C8H4N3Se2, a = 10.478 (4) Å, b = 10.780 (4) Å, c = 9.432 (4) Å, α = 107.16 (3)°, β = 115.23 (2)°, γ = 68.39 (3)°, V = 883.8 (6) Å3, Z = 4; 5 (E = S, α-phase), C8H4N3S2, a = 7.295 (3) Å, b = 20.488 (2) Å, c = 11.276 (2) Å, β = 95.54 (2)°, V = 1676.0 (7) Å3, Z = 8; 5 (E = Se), C8H4N3Se2, a = 7.364 (8) Å, b = 21.085 (2) Å, c = 11.119 (4) Å, β = 94.91 (5)°, V = 1720 (7) Å3, Z = 8; 5 (E = S, β-phase), C8H4N3S2, a = 8.782 (1) Å, b = 5.638 (1) Å, c = 17.128 (4) Å, β = 102.94 (2)°, V = 826.5 (6) Å3, Z = 4; 6 (E = Se), C8H4N3Se2, a = 7.301 (1) Å, b = 11.883 (2) Å, c = 10.186 (1) Å, β = 101.50 (1)°, V = 866.1 (5) Å3, Z = 4.

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 phosphazene, P 3 N 3 R 4 XX, where R is 3,5-dimethylpyrazole and XX is a spiro-bonded −NHCH 2 CH 2 CH 2 NH− ring, has P−N bonds of 1.554 (5)-1.614 (5) A in the phosphazene ring with exocyclic bonds of 1.609 (5) and 1.635 (5) A to the spiro ring and 1.683 (4)-1.708 (5) A to the pyrazole groups. The N−P−N angle within the phosphazene ring at the unique P atom is 6.9 (3)° smaller than those at the other P atoms. One of the pyrazole-substituted P atoms is displaced by 0.252 (5) A from the best plane of the other five ring atoms, which are coplanar to within 0.087 (6) A. The −PNCCCN− ring conformation is intermediate between a boat and a twist-boat

[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

C 18 H 14 Mn 2 O 6 Si cristalline dans P1 avec a=7,649, b=11,119 et c=12,203 A, α=98,39, β=104,68 et γ=96,29 o , Z=2; affinement jusqu'a R=0,039. Les deux cycles forment des angles diedres de 89,5 et 144,0 o avec le plan central et une unite Mn(CO) 3 est liee η 5 a chaque cycle

C 8 H 4 N 4 Se 2 2+ •2SbF 6 − •3C 7 H 5 N cristallise dans P1 avec a=6,829, b=13,981, c=21,320 A, α=72,26, β=89,03, γ=88,78 o , Z=2; affinement jusqu'a R=0,049. La maille cristalline contient quatre anions, six molecules de solvant et deux cations situes sur les centres d'inversion cristallographiques

[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

Cristallisation dans C2/c avec a=11,578, b=22,122 et c=13,672 A, β=110,31 o , Z=4; affinement jusqu'a R=0,046. Le cation est localise sur un centre cristallographique de symetrie et deux anions SbF 6 − independants sont localises chacun sur un axe de rotation d'ordre 2. L'un des anions est desordonne

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 Ru atom of the title complex, [Ru(C10H8N2)2-(H2O)2](PF6)2, is located on a crystallographic inversion center; the bipyridine ligands are bowed [dihedral angle between C5N planes is 162.68 (12) degrees] due to the interligand steric interactions of the trans bipyridyl units. The Ru--O distance is 2.116 (2) A and the mean Ru--N distance is 2.074 (2) A.

Sublimation of 1,2,3,5-dithiadiazolyl in vacuo affords a triclinic phase of the dimer [HCN2S2]2. The crystals belong to the space group P¯1, a = 6.816(3), b = 13.940(2), c = 14.403(3) Å, α = 116.830(14), β = 98.64(3), γ = 99.18(3)°, FW = 212.4 (for [HCN2S2]2·[N2]0.08) Z = 6. The crystal structure consists of stacked dimers, with three dimers per asymmetric unit. Pairs of asymmetric units, related by an inversion center, generate a pinwheel motif consisting of six dimers. The columnar structure associated with these pinwheels forms close-packed sets of “molecular tubes”. Cosublimation of the radical in the presence of iodine in the mole ratio (HCN2S2:I = 5:1) yields an iodine-doped hexagonal phase of composition [HCN2S2]6[I]1.1. Crystals of this material belong to the space group P61, a = b = 14.132(16), c = 3.352(5) Å, FW = 128.20, Z = 6. The crystal structure consists of sixfold pinwheels in which the now evenly spaced HCN2S2 rings form a spiral about the 61 axis. The iodine atoms lie within the columnar cavity of the pinwheels in a disordered array wrapped tightly about the sixfold screw axis. The single-crystal conductivity of the doped material is 15 S cm-1 at room temperature. Raman spectroscopic and magnetic susceptibility measurements on the doped material are reported.

The reaction of oxamidrazone with sulfur dichloride affords 4,4'-bis(1,2,3,5-dithiadiazolium) dichloride, which can be reduced with triphenylantimony to the corresponding bis(1,2,3,5-dithiadiazolyl) diradical; the solid state structure and transport properties of the dimer [S2N2CCN2S2]2 are reported.

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.

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

Preparation et etude par spectrometrie RMN des composes N 3 P 3 F 4 (C 6 H 5 )R(R=N(CH 3 ) 2 , n-C 4 H 9 ,t-C 4 H 9 ). Le compose avec R=t−C 4 H 9 cristallise dans le systeme orthorhombique, groupe Pmma et sa structure est affinee jusqu'a R=0,042

An expedient synthesis of previously unknown (1 Z , 3 Z )-1, 4-dibromobutadiene is reported. When this dibromide is treated with s- or t-butyllithium, (1 Z , 3 Z )-1-bromo-4-lithio-butadiene is generated. Treatment of the dibromide with four equivalents of t-butyllithium gives (1 Z , 3 Z )-dilithiobutadiene. Reaction of (1 Z , 3 Z )-1-bromo-4-lithiobutadiene with (η 5 -C 5 H 5 )Fe(CO) 2 I gives (1 Z , 3 Z )-(η 5 -C 5 H 5 )Fe-(CO) 2 CH=CHCH=CHBr. X-ray crystallographic analysis of this latter compound establishes the geometry about the bromobutadiene ligand.

Cristallisation dans le groupe P2 1 /c avec a=9,216, b=14,318 et c=10,229 A, β=104,57°, Z=4. Affinement jusqu'a R=0,037. La molecule est formee d'une unite norbornenyl avec deux groupes S 3 N attaches de facon exo aux positions 2,3. Effets des differents substituants sur l'energie de transition π*→π* des derives X-S 3 N

The oxidation of the cofacial dimer (I), which is in equilibrium with its remarkably stable radical (II), with nitrosonium salts yields the corresponding salts (III).

Cristallisation dans le groupe P2 1 /n avec a=6,563, b=11,717 et c=11,409 A, β=101,63 °, Z=4. Affinement jusqu'a R=0,042. Le cation S 4 N 4 H + se presente sous forme de cycle a 8 chainons en conformation bateau. Discussion a partir de calculs MNDO du rearrangement structural induit par la protonation de S 4 N 4

Crystals of the title sulfur compound are orthorhombic, Cmca, with a=9.872 (1), b=9.594 (1), and c=15.488 (1) A, V=1467.0 (4) A3, Z=4, and Dc =1.38 g cm−2. The final refinement using 537 observed reflections for 57 variable gave R=0.025. The non-isomorphous crystals of the selenium analog are also orthorhombic, Cmca, with a=9.300 (1), b=19.724 (1), c=8.064 (1) A, V=1479.1 (4) A, Z=4, and Dc =2.21 g cm−2. Refinement with 48 variables using 447 observed reflections gives R=0.041. In both structures the molecules have 2/m symmetry imposed by the lattice symmetry; the S (or Se) atoms of the central 4-membered ring are located on the rotation axis, and the P, exo S (or Se), and two carbon atoms of the t-butyl group lie on the mirror plane. The central rings are not readily hydrolyzed or oxidized by exposure to air, apparently as a result of steric protection provided by the t-butyl groups.

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.

(I), C 18 H 12 Mn 2 O 6 , cristallise dans P2 1 /C avec a=12,045, b=14,169 et c=11,468 A, β=115,91 o , Z=4, affinement jusqu'a R=0,043. (II), C 8 H 12 Mn 2 O 6 •1/2 C 6 H 6 , cristallise dans P1 avec a=7,850, b=9,205 et c=14,291 A, α=85,42, β=85,79 et γ=75,50 o , Z=2; affinement jusqu'a R=0,028. Ces deux cristaux presentent de grandes differences de conformation dans le coordinat dicyclopentadiene

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