Conformation of cationic N,N‐di­methyl­glycine in di­methyl­glycinium tri­fluoro­acetate

In the title compound, C₄H₁₀NO₂⁺·C₂F₃O₂^?, the main N—C—COOH skeleton of the protonated amino acid is nearly planar. The C=O/C—N and C=O/O—H bonds are syn and the two methyl groups are gauche to the methyl­ene H atoms. The conformation of the cation in the crystal is compared to that given by ab initio calculations (Hartree–Fock, self‐consistent field molecular‐orbital theory). The tri­fluoro­acetate anion has the typical staggered conformation with usual bond distances and angles. The cation and anion form dimers through a strong O—H?O hydrogen bond which are further interconnected in infinite zigzag chains running parallel to the a axis by N—H?O bonds. Weaker C—H?O interactions involving the methyl groups and the carboxy O atoms of the cation occur between the chains.     

Four tri­fluoro­methyl­nitro­benzene analogues

The crystal structures of four tri­fluoro­methyl­nitro­benzene analogues (CF₃)C₆H₃(NO₂)[C₄H₈N₂]R (where C₄H₈N₂ is piperazinyl and R is ethyl carboxyl­ate, CO₂C₂H₅, or phenyl, C₆H₅), have been determined, and their conformations and packing arrangements are compared. The four compounds are ethyl 4‐[4‐nitro‐2‐(tri­fluoro­methyl)­phenyl]­piperazine‐1‐car­boxyl­ate, (I), and ethyl 4‐[2‐nitro‐4‐(tri­fluoro­methyl)­phen­yl]piper­azine‐1‐carboxyl­ate, (II), both C₁₄H₁₆F₃N₃O₄, and 1‐­[4‐nitro‐2‐(tri­fluoro­methyl)­phenyl]‐4‐phenyl­piperazine, (III), and 1‐[2‐nitro‐4‐(tri­fluoro­methyl)­phenyl]‐4‐phenyl­piperazine, (IV), both C₁₇H₁₆F₃N₃O₂. All mol­ecules adopt a rod‐like conformation, while the asymmetric units of (II) and (IV) contain two unique mol­ecules that pack as monodirectional pairs. All mol­ecules pack with C—H⋯O/F close contacts to all but one of the O atoms and to five of the 18 F atoms.     

cis‐Di­chloro­(di­methyl­aminomethyl­ene)­(tri­phenyl­phosphine)palladium(II) acetone solvate

The synthesis and X‐ray structural analysis of the title compound, [PdCl₂(C₃H₇N)(C₁₈H₁₅P)]·C₃H₆O, are described. The crystal structure contains discrete monomeric mol­ecules of the carbene complex and solvent mol­ecules separated by normal van der Waals distances. The Pd atom is four‐coordinate in an essentially square‐planar environment, with the chlorine ligands mutually cis; Pd—P = 2.2495 (7), Pd—Cl = 2.3508 (7) and 2.3600 (7), Pd—C 1.948 (2) and N—C(carbene) 1.274 (3) Å.     

Methyl­tri­phenyl­stibonium tetra­fluoro­borate

In the title compound, [Sb(CH₃)(C₆H₅)₃]BF₄, there are four independent cations and anions in the asymmetric unit. The geometry around the Sb atom is distorted tetrahedral, with Sb—C distances in the range 2.077 (4)–2.099 (10) Å and angles at the Sb atom in the range 103.3 (3)–119.0 (4)°.     

Di­chloro­bis(3,5‐di­methyl­pyrazole‐N2)methyl­phenyl­tin(IV)

The title compound, [SnCl₂(CH₃)(C₆H₅)(C₅H₈N₂)₂], was obtained by reaction of di­chloro­methyl­phenyl­tin(IV) and 3,5‐di­methyl­pyrazole (dmpz) in chloro­form, and was recrystallized from acetone. The structure consists of octahedral all‐trans [SnMePhCl₂(dmpz)₂] mol­ecules, with the Sn atom coordinated to two C [Sn—C 2.127 (5) and 2.135 (4) Å], two Cl [Sn—Cl 2.5753 (8) Å] and two N atoms [Sn—N 2.357 (3) Å]. The dmpz ligands, bound to the metal through their unprotonated N atoms, form weak intra‐ and intermolecular hydrogen bonds with the Cl ligands via their NH groups, giving rise to a polymeric chain along the c axis.     

Rubidium bis­(tri­fluoro­methane­sulfonyl)­imidate dioxane disolvate

The bis­(tri­fluoro­methane­sulfonyl)­imidate anion crystallizes with Rb as the title dioxane 1:2 solvate, Rb⁺·CF₃SO₂NSO₂CF₃⁻·2C₄H₈O₂, with the anion in a transoid conformation, as opposed to the cisoid form typically seen when there are significant cation–anion interactions. The Rb^I cation is eight‐coordinate, interacting with one anion in a chelating fashion and with two other anions through the remaining sulfonyl O atoms. The latter interactions link ion pairs through the formation of Rb₂O₂ dimers about inversion centers at (0, , 0) and (, , 0), forming extended columns which run parallel to the a axis of the unit cell. Rb–dioxane bridges crosslink these salt columns in the (010), (001) and (011) directions, resulting in a three‐dimensional network solid. One dioxane solvent mol­ecule is disordered over two half‐occupancy sites.     

Triclinic polymorphs of tri­phenyl­phosphine and tri­phenyl­phosphine sulfide

New triclinic polymorphs of tri­phenyl­phosphine, (I), and tri­phenyl­phosphine sulfide, (II), were crystallized. For the structure of (I), it is obvious that the highest peaks in the final difference electron‐density map are located at the `lone‐pair regions' of P atoms. We have observed this effect in two further phosphorous‐containing structures.     

Sarcosinium tri­fluoro­acetate

The title compound, C₃H₈NO₂⁺·C₂F₃O₂^?, crystallizes in space group C2/c. The main N—C—COOH skeleton of the protonated sarcosine mol­ecule is almost perfectly planar. The tri­fluoro­acetate anion has a staggered conformation and typical bond distances and angles. The CF₃ group is probably slightly disordered. The structure is stabilized by an extensive network of strong O—H?O hydrogen bonds and weaker N—H?O bonds.     

Betainium tri­fluoro­acetate

The title compound, C₅H₁₂NO₂⁺·C₂F₃O₂^? or BET⁺·CF₃COO^? [BET is tri­methyl­glycine (betaine); IUPAC: 1‐carboxy‐N,N,N‐tri­methyl­methanaminium inner salt], contains pairs of bet­ainium and tri­fluoro­acetate ions forming a dimer bridged by a strong hydrogen bond between the carboxyl and carboxyl­ate groups of the two ions. The molecular symmetry of the cation is close to C_s, with protonation occurring at the carboxy O atom positioned anti to the N atom. The tri­fluoro­acetate anions are disordered over two positions. In one, the conformation of the CF₃ group is staggered with respect to the carboxyl­ate group, in the other, it is close to an eclipsed conformation. The sole hydrogen bond present in the structure is the strong O—H?O bond between the anion and the cation.     

3,5‐Di­methyl‐4‐(2,4,6‐tri­methyl­phenyl­diazenyl)­phenol

In the title compound, C₁₇H₂₀N₂O, (I), the dihedral angle between the two phenyl rings is 15.69 (6)°. An intermolecular hydrogen‐bonding association exists between the hydroxy group and one of the azo N atoms.     

The centrosymmetric dimer of di­chloro­(tri­methyl­siloxy)­aluminium

The title mol­ecule is dimeric, i.e. di‐μ‐tri­methyl­siloxy‐bis­(di­chloro­aluminium), [Al₂Cl₄(C₃H₉Si)₂], and possesses exact crystallographic inversion symmetry. The O atoms of the tri­methyl­siloxy groups bridge the two Al atoms to form a four‐membered ring. The Si—O bond distance [1.711 (3) Å], the Al—O mean bond distance [1.806 (4) Å] and the mean Si—C bond distance [1.875 (6) Å] appear to agree well with standard data. Mean values for C—Si—C, O—Si—C, and Si—O—Al angles are 112.9 (3), 105.8 (2), and 131.8 (2)° repectively. The two ring angles O—Al—O and Al—O—Al are 84.43 (16) and 95.57 (16)°, respectively.     

The effects of substitution on tetrakis­(substituted imidazole)­copper(II) tri­fluoro­methane­sulfonates

The organic ligands 4‐methyl‐1H‐imidazole and 2‐ethyl‐4‐methyl‐1H‐imidazole react with Cu(CF₃SO₃)₂·6H₂O to give tetrakis(5‐methyl‐1H‐imidazole‐κN³)­cop­per(II) bis­(tri­fluoro­methane­sulfonate), [Cu(C₄H₆N₂)₄](CF₃SO₃)₂, and aqua­tetrakis(2‐ethyl‐5‐methyl‐1H‐imidazole‐κN³)copper(II) bis(tri­ fluoro­methane­sulfonate), [Cu(C₆H₁₀N₂)₄(H₂O)](CF₃SO₃)₂. In the former, the Cu atom has an elongated octahedral coordination environment, with four imidazole rings in equatorial positions and two tri­fluoro­methane­sulfonate ions in axial positions. This conformation is similar to those in the analogous complexes tetrakis­(imidazole)­cop­per(II) tri­fluoro­methane­sulfonate and tetrakis(2‐methyl‐1H‐imidazole)­cop­per(II) tri­fluoro­methane­sulfonate. In the second of the title compounds, the ethyl groups block the central Cu atom, and a square‐pyramidal coordination environment is formed around the Cu atom, with the substituted imidazole rings in the basal positions and a water mol­ecule in the axial position.     

Sodium trichloro­methane­sulfonate monohydrate

Sodium trichloro­methane­sulfonate monohydrate, Na⁺·CCl₃SO₃⁻·H₂O, crystallizes in P2₁/a with all the atoms located in general positions. The trichloro­methane­sulfonate (trichlate) anion consists of pyramidal SO₃ and CCl₃ groups connected via an S—C bond in a staggered conformation with approximate C_3v symmetry. The water mol­ecule is hydrogen bonded to the sulfonate O atoms, with one water H atom forming weak bifurcated O—H⋯O hydrogen bonds to two different trichlate ions. Two water O atoms and three O atoms from different SO₃ groups form a square‐pyramidal arrangement around the sodium ion.     

trans‐Di­chloro­bis­(tri­phenyl­phosphine‐P)­platinum(II)

Two different crystals (A and B) were used to structurally characterize trans‐[PtCl₂(PPh₃)₂] and to study random and systematic errors in derived parameters. The compound is isomorphous with trans‐[PdCl₂(PPh₃)₂] and with one of the polymorphs of trans‐[PtMeCl(PPh₃)₂] reported previously. Half‐normal probability plot analyses based on A and B show realistic s.u.'s and negligible systematic errors. R.m.s. calculations give very good agreement between A and B, 0.0088 Å. Important geometrical parameters are Pt—P = 2.3163 (11) Å, Pt—Cl = 2.2997 (11) Å, P—Pt—Cl = 87.88 (4) and 92.12 (4)°. Half‐normal probability plots and r.m.s. calculations were also used to compare the title compound with the palladium analogue, showing small systematic differences between the compounds. The torsion angles around the Pt—P bond were found to be very similar to those reported for isomorphous complexes, as well as to the torsion angles around the Pt—As bond in trans‐[PtCl₂(AsPh₃)₂]. The NMR coupling constants for the title compound are similar to Pt—P coupling constants reported for analogous trans complexes.     

Pefloxacinium methane­sulfonate 0.10‐hydrate

The crystal structure of 4‐(3‐carboxy‐1‐ethyl‐6‐fluoro‐1,4‐di­hydro‐4‐oxo‐7‐quinolyl)‐1‐methyl­piperazinium methane­sulfonate 0.10‐hydrate, C₁₇H₂₁FN₃O₃⁺·CH₃O₃S^?·0.10H₂O, contains pefloxacinium cations, methane­sulfonate anions and a partially occupied water of solvation. The quinoline ring system in the cation is essentially planar. The anions lie parallel to each other about inversion centers. The structure is stabilized by strong hydrogen bonds involving the terminal piperazinyl‐N atom of the cation and an O atom of the anion [N?O 2.739 (2) Å], and a strong intramolecular hydrogen bond between carbonyl and carboxyl groups [O?O 2.523 (2) Å].     

The twinned structure of ferricenyl­tri­fluoro­borate

Crystals of the title compound, [Fe(C₅H₅)(C₅H₄BF₃)], are monoclinic and twinned. The twinning initially resulted in a misleading unit‐cell assignment. The formal oxi­dation state of Fe is 3+, and the crystal packing consists of intermolecular C—H...F and π–π interactions.     

Ethyl­tri­phenyl­phospho­nium perrhenate and (iodo­methyl)­tri­phenyl­phospho­nium perrhenate

Ethyl­tri­phenyl­phospho­nium perrhenate, (C₂₀H₂₀P)[ReO₄], and (iodo­methyl)­tri­phenyl­phospho­nium perrhenate, (C₁₉H₁₇IP)[ReO₄], have been crystallized from 2‐propanol. Both crystal structures consist of phospho­nium cations and perrhenate anions. The cations show the typical propeller‐like geometry. In both crystals, the positions of the nearly tetrahedral anions are stabilized by weak C—H⋯O hydrogen bonds, and for the latter compound, I⋯π interactions also occur.     

trans‐(Methanol)(methyl­di­phenyl­phosphine)­bis­(pentane‐2,4‐dionato)­cobalt(III) hexa­fluoro­phosphate hydrate

The title compound [Co(C₅H₇O₂)₂(C₁₃H₁₃P)(CH₄O)]PF₆·H₂O, (I), which was converted from trans‐[Co(acac)₂(PMePh₂)(H₂O)]PF₆ (acac is pentane‐2,4‐dionato) by recrystallization from aqueous methanol, has been confirmed as have a coordinated methanol ligand. The molecular structure of the complex cation, trans‐[Co(acac)₂(PMePh₂)(MeOH)]⁺, is similar to that of the above aqua complex found in the ClO₄ salt [Kashiwabara et al. (1995). Bull. Chem. Soc. Jpn, 68 , 883–888]. The Co—O bond length for the coordinated methanol is 2.059 (3) Å. There is an intermolecular hydrogen bond between the OH group of the coordinated methanol and one of the O atoms of the acac ligands in an adjacent complex cation [O5?O3′ = 2.914 (4) Å], giving a centrosymmetric dimeric dicationic complex.     

5,6‐Di­phenyl­[1,3]­di­thiolo­[4,5‐b]di­thiine‐2‐thione

In the title compound, C₁₇H₁₀S₅, the dithiine ring adopts a boat conformation while the di­thiole ring has an envelope conformation. The phenyl groups are planar and make dihedral angles of 40.7 (2) and 59.8 (2)° with the best plane of the thiine ring. The shortest intermolecular S?S contact is 3.305 (2) Å.     

Aqua­bis­(benzo­nitrile)(o‐benzo­quin­one di­imine)(tri­phenyl­phosphine)­ruthenium(II) bis­(tetra­fluoro­borate) hydrate

The Ru atom in the title compound, [Ru(C₆H₅CN)₂{P(C₆H₅)₃}{C₆H₄(NH)₂}(H₂O)](BF₄)₂·H₂O, has six‐coordinate octahedral geometry, with a trans arrangement of the tri­phenyl­phosphine ligand and the water mol­ecule. The asymmetric unit contains one complex cation, two tetra­fluoro­borate anions and one solvent water mol­ecule, which is disordered over two sites (ratio of occupancies 0.70:0.30).