A polymorph of tetrakis(acetonitrile‐κN)copper(I) tetrafluoridoborate

A P2₁2₁2₁ polymorph of the title compound, [Cu(CH₃CN)₄]BF₄, is reported. The crystal structure is very similar to the structure of the Pna2₁ polymorph reported by Jones & Crespo [Acta Cryst. (1998), C 54 , 18–20]. The anions and one of the three independent cations occupy similar positions in both polymorphs. Two of the four symmetry‐related positions of the other two cations are also identical in the two polymorphs, and the other two positions are related by mirror symmetry. The crystal used for the structure determination contained a volume fraction of 0.088 (7) of the Pna2₁ polymorph.     

[Bis(3,5‐dimethylpyrazol‐1‐yl‐κN2)dithioacetato‐κS](triphenylphosphine‐κP)copper(I)

In the title compound, [Cu(C₁₂H₁₅N₄S₂)(C₁₈H₁₅P)], the copper(I) center is tetrahedrally coordinated by one S atom and two N atoms from one bis(3,5‐dimethylpyrazol‐1‐yl)dithioacetate ligand and one P atom from a triphenylphosphine ligand. In the crystal structure, adjacent pyrazole rings are involved in weak π–π interactions, thereby forming a one‐dimensional zigzag chain running along the b axis.     

cis‐Dichloridobis(diethyl sulfide‐κS)platinum(II) at 295 and 150 K

The title compound, cis‐[PtCl₂(C₄H₁₀S)₂], crystallizes in the space group P2₁/n with pseudo‐square‐planar coordination geometry. The orientation of the ethyl groups on the S atoms is staggered with respect to the coordination plane, giving the complex approximate C_2v symmetry. The complex does not form dimeric packing units with short Pt...S intradimeric distances as seen in some related complexes, but instead displays C—H...Cl interactions in three dimensions. These C—H...Cl—Pt contacts are compared with those of related compounds reported in the Cambridge Structural Database, which show a frequency maximum in the range 120–170° for the C—H...Cl angle.     

[4‐Amino‐N‐(pyrimidin‐2‐yl)benzenesulfonamido‐κN](triphenylphosphine‐κP)gold(I)

The title compound, [Au(C₁₀H₉N₄O₂S)(C₁₈H₁₅P)], is nearly linear at Au^I, with Au—N = 2.0707 (18) Å, Au—P = 2.2310 (8) Å and N—Au—P 171.93 (5)°. The mol­ecules are linked by intermolecular N—H⃛O bonds.     

[Bis(2‐diphenylphosphinoethyl) sulfide‐κ3P,S,P′](triphenylphosphine‐κP)platinum(II) diperchlorate acetone solvate

In the title compound, [Pt(C₁₈H₁₅P)(C₂₈H₂₈P₂S)]­(ClO₄)₂·­C₃H₆O or [Pt(PPh₃)(PSP)](ClO₄)₂·CH₃COCH₃, where PSP is the potentially tridentate chelate ligand bis(2‐di­phenyl­phosphinoethyl) sulfide, all three donor groups of the PSP ligand are coordinated to the central Pt atom, with Pt—P = 2.310 (1) Å and Pt—S = 2.343 (1) Å. The fourth coordination site is occupied by the P donor of the tri­phenyl­phosphine ligand [Pt—P = 2.289 (1) Å]. The complex cation has exact mirror symmetry, with the S atom, the Pt atom and the P atom of the PPh₃ ligand in the mirror plane. The Pt atom has a distorted square‐planar coordination geometry. A π–π interaction is present between the phenyl rings of the PPh₃ ligand and the terminal –PPh₂ group of the PSP chelate.     

A second monoclinic polymorph of S‐­(4‐tolyl) 4‐toluenethiosulfonate at 150 and 293 K

The title compound, C₁₄H₁₄O₂S₂, contains discrete mol­ecules and is a polymorph of a structure reported previously by Caputo, Palumbo, Nardelli & Pelizzi [Gazz. Chim. Ital. (1984), 114 , 421–430]. The present structure contains no intermolecular C—H?O hydrogen bonds, whereas in the previous polymorph, the mol­ecules are linked into continuous chains by such interactions.     

A triclinic polymorph of cyclo‐tetra‐μ‐thiosaccharinato‐κ8S:S‐tetrakis[(triphenylphosphane‐κP)silver(I)]

The triclinic structure of the title compound, cyclo‐tetrakis(μ‐1,1‐dioxo‐1λ⁶,2‐benzothiazole‐3‐thiolato‐κ²S:S)tetrakis[(triphenylphosphane‐κP)silver(I)], [Ag₄(C₇H₄NO₂S₂)₄(C₁₈H₁₅P)₄], is a polymorph of the previously reported monoclinic structure [Dennehy, Mandolesi, Quinzani & Jennings (2007). Z. Anorg. Allg. Chem. 633 , 2746–2752]. In both polymorphs, the complex lies on a crystallographic inversion centre and the bond distances are closely comparable. Some differences can be found in the interatomic angles and torsion angles involving the inner Ag₄S₄ skeleton. The polymorphs contain essentially identical two‐dimensional layers, but with different layer stacking arrangements. In the triclinic form, all layers are related by lattice translation, while in the monoclinic form they are arranged around glide planes so that adjacent layers are mirrored with respect to each other.     

Di­chloro­bis­(imidazolidin‐2‐one‐κO)­zinc(II) at 150 K

In the title compound, [ZnCl₂(C₃H₆N₂O)₂], the zinc(II) cation is surrounded by a distorted tetrahedral environment consisting of two Cl anions and two imidazolidin‐2‐one mol­ecules, the latter bound to the metal through their carbonyl O atoms. All atoms that are able to participate in hydrogen bonding are involved in such interactions. A hydrogen‐bonding network mediates the formation of mol­ecular columns parallel to the a axis. Neighboring columns are not bound by significant non‐covalent interactions; the result is an extended pattern of supramolecular aggregation that is intermediate in completeness between the situations observed in two related complexes of cobalt that have been studied previously.     

N‐Benzylformamide at 150 K

The title compound, C₈H₉NO, crystallizes with Z′ = 2. Each type of independent molecule links into a separate N—H...O hydrogen‐bonded chain in the a‐axis direction. There are also three weak C—H...O hydrogen bonds, which join the molecules into a two‐dimensional sheet parallel to (001). The molecules exhibit the trans conformation of the –NHCHO group and an anti conformation around the (Ph)C—NH(CHO) bond. The formamide group in each of the symmetry‐independent molecules is twisted out of the benzyl group plane, forming angles of 75.96 (10) and 65.23 (11)° with this plane. The significance of this study lies in the comparison drawn between the experimental and calculated data of the crystal structure of the title compound and the data of several other derivatives possessing the –CH₂—NH—CO– group. The correlation between the IR spectrum of this compound and the hydrogen‐bond energy is also discussed. This molecular system is of particular interest to biochemists because of its preventative function against toxic products of alcohols in human metabolism.     

A new polymorph of (O‐ethyl dithio­carbonato‐κ2S,S′)­bis­(tri­phenylphosphine‐κP)silver(I)

A new triclinic polymorphic modification of the title compound, [Ag(C₃H₅OS₂)(C₁₈H₁₅P)₂], has been found and compared with the previously known orthorhombic modification [Tiekink (1988). Coord. Chem. 17 , 239–243]. The two polymorphs have the same molecular shape, viz. a distorted tetrahedral geometry, with a chelating di­thio­carbonate (xanthate) and two PPh₃ ligands bonded to the Ag atom. However, in this new polymorph, the xanthate ligand is bonded asymmetrically to the Ag atom, with Ag—S distances of 2.5489 (6) and 2.8055 (7) Å, while for the orthorhombic polymorph these distances are 2.686 (4) and 2.601 (4) Å. The Ag—P distances are similar in both structures.     

trans‐Carbonylchloridobis(ferrocenyldiphenylphosphane‐κP)rhodium(I) dichloromethane monosolvate and trans‐carbonylchloridobis(ferrocenyldiphenylphosphane‐κP)iridium(I) dichloromethane monosolvate

The isomorphous crystal structures of the title compounds, [Fe₂M(C₅H₅)₂(C₁₇H₁₄P)Cl(CO)]·CH₂Cl₂ or trans‐[MCl(CO)(PPh₂Fc)₂]·CH₂Cl₂ (M = Rh or Ir, and Fc is ferrocenyl), are reported. The data collection for M = Rh was performed at 293 (2) K, while the M = Ir data were collected at 160 (2) K. The compounds crystallize with two independent half‐molecules in the asymmetric unit, both occupying inversion centres, and are accompanied by a single dichloromethane molecule on a general position. Due to the symmetry, there is 0.50/0.50 disorder present in the chloride and carbonyl positions. One molecule in each structure also has a second type of disorder in the chloride and carbonyl positions, which was refined over another two positions of equal distribution. The steric impact of the bulky PPh₂Fc ligands was evaluated using the Tolman cone‐angle model, resulting in an average value of 172° for the four molecules in both structures.     

Bis{2,6‐bis[3‐(2,4,6‐trimethylphenyl)pyrazol‐1‐yl‐κN2]pyridine‐κN}cobalt(II) dinitrate at 290 and 150 K

The title compound, [Co(C₂₉H₂₉N₅)₂](NO₃)₂, contains a six‐coordinate high‐spin Co^II ion with approximate local D_2d symmetry. The bond lengths and angles at cobalt undergo only small changes between the two temperatures, which confirms that the Co^II ion does not undergo a spin‐state transition over this temperature range.     

trans‐[1,3‐Bis(2,4,6‐trimethylphenyl)imidazolidin‐2‐ylidene]dichlorido(triphenylphosphine‐κP)palladium(II)

The title complex, [PdCl₂(C₂₁H₂₆N₂)(C₁₈H₁₅P)], shows slightly distorted square‐planar coordination around the Pd^II metal centre. The Pd—C bond distance between the N‐heterocyclic ligand and the metal atom is 2.028 (5) Å. The dihedral angle between the two trimethylphenyl ring planes is 36.9 (2)°.     

(2,6‐Bis{1‐[4‐(dimethylamino)phenylimino]ethyl}pyridine)dichlorido(triphenylphosphine‐κP)ruthenium(II): a zigzag chain of fused centrosymmetric R22(12) rings

The title compound, [RuCl₂(C₂₅H₂₉N₅)(C₁₈H₁₅P)], a transfer hydrogenation catalyst, is supported by an N,N′,N′′‐tridentate pyridine‐bridged ligand and triphenylphosphine. The Ru^II centre is six‐coordinated in a distorted octahedral arrangement, with the two Cl atoms located in the axial positions, and the pyridine (py) N atom, the two imino N atoms and the triphenylphosphine P atom located in the equatorial plane. The two equatorial Ru—N_imino distances (mean 2.093 Å) are substantially longer than the equatorial Ru—N_py bond [1.954 (4) Å]. It is observed that the N_imino—M—N_py bond angle for the five‐membered chelate rings of 2,6‐bis(imino)pyridine‐based complexes is inversely related to the magnitude of the M—N_py bond. The title structure is stabilized by intra‐ and intermolecular C—H...Cl hydrogen bonds, as well as by intramolecular π–π stacking interactions between the aromatic rings belonging to the triphenylphosphine ligand and the dimethylaminophenyl fragment. The intermolecular hydrogen bonds form an R₂²(12) ring and a zigzag chain of fused centrosymmetric rings running parallel to the [100] direction.     

Redetermination of ternifoline‐C at 150 K

The relative stereochemistry of ternifoline‐C (7,20‐epoxy‐ent‐kaur‐16‐ene‐1,6,7,15‐tetrol 1‐acetate), C₂₂H₃₂O₆, previously reported by Wu [FudanXuebaoZir. Kex. (1988), 27 , 61–65], has been redetermined at 150 K. The molecular geometry and crystal packing agree well with the previous study.     

4‐Ethynyl‐1,2‐methylenedioxybenzene at 150 K

The title compound, C₉H₆O₂, contains two moderate C—H?O hydrogen bonds. That involving the terminal alkyne gives rise to chains along the b axis. The other hydrogen bond occurs over a centre of symmetry, leading to dimers. The combination of the two interactions gives rise to rings, each comprising six mol­ecules, which are part of infinite sheets in the bc plane.     

4‐(Piperidin‐1‐yl)pyridinium hexafluorophosphate at 150 K

Structural characterization of the title compound, C₁₀H₁₅N₂⁺·PF₆⁻, shows it to be ionic, with the pyridine rather than the piperidine N atom being protonated and forming hydrogen bonds to the counter‐ions, resulting in two independent ion pairs. A number of unusual features are noted, in particular the remarkably close inter‐ring hydrogen contacts [1.97 (3)–2.00 (3) Å] and the considerable differences in the pair of cations, in respect of the torsion angles within the piperidine ring involving the bonds to either side of the N atom.     

Bis(tetra‐n‐butylammonium) (a redetermination at 150 K) and bis(tetraphenylarsonium) bis(1,3‐dithiole‐2‐thione‐4,5‐dithiolato)zinc(II) (at 300 K)

The title compounds are salts of the general form (Q⁺)₂[Zn(dmit)₂]^2?, where dmit corresponds to the ligand (C₃S₅)^? present in both and Q⁺ to the counter‐cations (ⁿBu₄N)⁺ [or C₁₆H₃₆N⁺] and (Ph₄As)⁺ [or C₂₄H₂₀As⁺], respectively. In the first case, Zn is in the 4e special positions of space group C2/c and hence the [Zn(dmit)₂]^2? dianion possesses twofold axial crystallographic symmetry. Including these, there are now 11 known examples of [Zn(dmit)₂]^2? or its analogues, with O replacing the exocyclic thione S, and [Zn(dmio)₂]^2? dianions in nine structures with various Q. Comparison of these reveals a remarkable variation in details of the conformation which the dianion may adopt in terms of Zn coordination, equivalence of the Zn—S bond lengths, displacement of Zn from the plane of the ligand and overall dianion shape.     

2,4,5,7‐Tetra­methyl­phenanthrene at 150 K

The title compound, C₁₈H₁₈, crystallized in the centrosymmetric space group P2₁/c with one mol­ecule as the asymmetric unit. The methyl‐group H atoms at the 4 and 5 positions are ordered, while those at the 2 and 7 positions are disordered. The torsion of the bay region of the core is notably similar to that of other 4,5‐di­methyl­phenanthrenes. No substantial C—H?π interaction occurs in this structure.