(2S,RS)‐6‐Phenyl‐1‐(p‐tolyl­sulfinyl)­hexa‐3(E),5(E)‐dien‐2‐ol

The mol­ecule of the title compound, C₁₉H₂₀O₂S, corresponds to a chiral sulfinyldienol with two stereogenic centres, viz. the C atom susbtituted by the hydr­oxy group and the sulfinyl S atom. The mol­ecule displays a V‐shape in the solid state. The dihedral angle defined by the least‐squares planes of the aromatic rings is 72.9 (1)°. The packing pattern exhibits the following inter­molecular hydrogen bonds: one O—H⋯O [H⋯O = 1.98 Å, O⋯O = 2.785 (4) Å and O—H⋯O = 166°] and two C—H⋯O [H⋯O = 2.58 and 2.60 Å, C⋯O = 3.527 (5) and 3.347 (5) Å, and C—H⋯O = 164 and 134°]. These define a chain along b.     

1‐(4‐Bromo­phenyl)‐3‐(4‐methyl­phenyl)­prop‐2‐en‐1‐one

In the mol­ecule of the title compound, C₁₆H₁₃BrO, the two benzene rings are rotated in opposite directions with respect to the central C—C=C—C part of the mol­ecule. The phenone O atom deviates from the least‐squares plane of the mol­ecule by 0.300 (3) Å. In the crystal structure, mol­ecules are paired through C—H⋯π interactions. The molecular pairs along [001] are hydrogen bonded through three translation‐related co‐operative hydrogen bonds in the `bay area', forming molecular chains, which are further hydrogen bonded through C—H⋯Br weak interactions, forming (010) molecular layers. In the third direction, there are only weak van der Waals interactions. The co‐operative hydrogen bonds in the `bay area' are discussed briefly.     

[1,3‐Bis(2‐ethoxy­phenyl)imidazolidin‐2‐yl­idene]bromo­(cyclo­octa‐1,5‐diene)­rhodium(I)

The title complex, [RhBr(C₈H₁₂)(C₁₉H₂₂N₂O₂)], has a distorted square‐planar geometry. There are two mol­ecules, A and B, in the asymmetric unit. The Rh—C bond distance between the N‐heterocyclic ligand and the metal atom is 2.039 (2) Å in mol­ecule A and 2.042 (2) Å in mol­ecule B. The angle between the carbene heterocycle and the coordination plane is 87.56 (12)° in mol­ecule A and 87.03 (11)° in mol­ecule B. It is shown that the average Rh—C(COD) (COD is cyclo­octa­diene) distance is linearly dependent on the Rh—C(imidazolidine) distance in this type of compound. This can be ascribed to the steric hindrance produced by the packing. The crystal structure contains intra­molecular C—H⋯O and inter­molecular C—H⋯Br inter­actions.     

7,8‐Dihydr­oxy‐4‐propyl‐1,2,3,4,4a,5,6,10b‐octa­hydro­benzo[f]quinolinium bromide monohydrate,a dopamine agonist

In the crystal structure of the title dopamine­rgic compound, C₁₆H₂₄NO₂⁺·Br⁻·H₂O, protonation occurs at the piperidine N atom. The piperidine ring adopts a chair conformation and the cyclo­hexene ring adopts a half‐chair conformation; together with the planar benzene ring, this results in a relatively planar shape for the whole mol­ecule. Classical hydrogen bonds (N—H⋯Br, O—H⋯Br and O—H⋯O) produce an infinite three‐dimensional network. Hydrogen bonds between water ­mol­ecules and Br⁻ anions create centrosymmetric rings throughout the crystal structure. Structural comparison of the mol­ecule with the ergoline dopamine agonist pergolide shows that it is the hydrogen‐bond‐forming hydr­oxy or imino group that is necessary for dopamine­rgic activity, rather than the presence of a phenyl or a pyrrole ring per se.     

Dichloro­(O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid‐κ2N,N′)copper(II)

In the title compound, [CuCl₂(C₉H₁₂N₂O)], the Cu^II atom is coordinated by two Cl⁻ anions and two N atoms of one O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid mol­ecule in a slightly distorted square‐planar geometry, with Cu—N distances of 2.0483 (17) and 1.9404 (18) Å, and Cu—Cl distances of 2.2805 (10) and 2.2275 (14) Å. In addition, each Cu^II atom is connected by one Cl⁻ anion and the Cu^II atom from a neighbouring mol­ecule, with Cu⋯Cl and Cu⋯Cu distances of 2.9098 (13) and 3.4022 (12) Å, respectively, and, therefore, a centrosymmetric dimer is formed. Adjacent mol­ecular dimers are connected by π–π stacking inter­actions between pyridine rings to form a zigzag mol­ecular chain. The mol­ecular chains are also enforced by N—H⋯Cl and C—H⋯Cl inter­actions.     

2′‐(4‐Fluoro­phenyl)‐[1,2,3]­triazolo[4′,5′:16,17]­androst‐5‐en‐3β‐ol methanol hemisolvate

The asymmetric unit of the title compound, C₂₅H₃₀FN₃O·0.5CH₃OH, contains four symmetry‐independent steroid and two methanol mol­ecules. The conformations of the independent steroid mol­ecules are very similar. Intermolecular O—H⋯O hydrogen bonds create two independent chains, each of which links two of the independent steroid mol­ecules plus one methanol mol­ecule via a co‐operative O—H⋯O—H⋯O—H pattern. Intermolecular C—H⋯O and C—H⋯F interactions are also observed.     

4‐[(2‐Chloro­phenyl)­diazenyl]‐6‐methoxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one

The structure of the title compound, C₁₈H₂₀ClN₃O₅, displays the characteristic features of azo­benzene derivatives. Intramolecular N—H⋯O, weak intramolecular C—H⋯O, and intermolecular O—H⋯O and C—H⋯O interactions influence the conformation of the mol­ecules and the crystal packing. Intermolecular hydrogen bonds link the mol­ecules into infinite chains, and the title compound adopts the keto–amine tautomeric form. The azo­benzene moiety of the mol­ecule has a trans configuration. The mol­ecule is not planar, and the dihedral angle between the two phenyl rings is 35.6 (2)°.     

Dichloro­[(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane]zinc(II) and di‐μ‐chloro‐bis­{chloro­[(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane]cadmium(II)}

The Zn atom in dichloro­[(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)­methane]zinc(II), [ZnCl₂(C₁₁H₁₆N₄)], (I), is tetra­hedrally coordinated by two N atoms from one bis­(3,5‐dimethyl­pyrazol­yl)methane ligand and two terminal Cl atoms. The mol­ecule has no crystallographic symmetry. One H atom of the CH₂ group of the bis­(3,5‐dimethyl­pyrazol­yl)methane ligand inter­acts with a Cl atom of an adjacent mol­ecule to yield inter­molecular C—H⋯Cl contacts, thereby forming a one‐dimensional zigzag chain extending along the b axis. On the other hand, in di‐μ‐chloro‐bis­{chloro­[(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane]cadmium(II)}, [Cd₂Cl₄(C₁₁H₁₆N₄)₂], (II), each of the two crystallographically equivalent Cd atoms is penta­coordinated by two N atoms from one bis­(3,5‐dimethyl­pyrazol­yl)methane ligand, and by one terminal and two bridging Cl⁻ anions. The mol­ecule has a crystallographic centre of symmetry located at the mid‐point of the Cd⋯Cd line. One H atom of the CH₂ group of the bis­(3,5‐dimethyl­pyrazolyl)­methane ligand inter­acts with a Cl atom of an adjacent mol­ecule to produce pairwise inter­molecular C—H⋯Cl contacts, thereby affording chains of mol­ecules running along the c axis.     

Tris(1H‐benzimidazol‐2‐yl­meth­yl)­amine–solvent adducts

The tris­(1H‐benzimidazol‐2‐yl­meth­yl)­amine (ntb) mol­ecule crystallizes in different solvent systems, resulting in two kinds of adduct, namely the monohydrate, C₂₄H₂₁N₇·H₂O or ntb·H₂O, (I), and the acetonitrile–methanol–water (1/0.5/1.5) solvate, C₂₄H₂₁N₇·C₂H₃N·0.5CH₄O·1.5H₂O or ntb·1.5H₂O·0.5MeOH·MeCN, (II). In both cases, ntb adopts a tripodal mode to form hydrogen bonds with a solvent water mol­ecule via two N—H⋯O and one O—H⋯N hydrogen bond. In (I), the ntb·H₂O adduct is further assembled into a two‐dimensional network by N—H⋯N and O—H⋯N hydrogen bonds, while in (II), a double‐stranded one‐dimensional chain structure is assembled via N—H⋯O and O—H⋯O hydrogen bonds, with the acetonitrile mol­ecules located inside the cavities of the chain structure.     

2‐[(2‐Hydro­xy‐4‐nitro­phenyl)­amino­methyl­ene]­cyclo­hexa‐3,5‐dien‐1(2H)‐one

The title compound, C₁₃H₁₀N₂O₄, adopts the keto–amine tautomeric form and displays an intramolecular N—H⋯O [N⋯O = 2.579 (2) Å] and three intermolecular O—H⋯O [O⋯O = 2.561 (2) Å] and C—H⋯O [C⋯O = 3.274 (2) and 3.318 (2) Å] hydrogen bonds. The keto–amine structure is favoured by through‐mol­ecule conjugation between the hydroxy O atom and imine N atom. The dihedral angle between the planes of the two aromatic rings is 10.79 (4)°.     

A new tricarbonyl­rhenium(I) compound incorporating the tridentate ligand N,N‐bis­picol­yl‐2‐ethano­lamine

The title compound, {[N,N‐bis­(2‐pyridylmeth­yl)­amino]­ethanol‐κ³N,N′,N′′}tricarbonyl­rhenium(I) bromide methanol solvate, [Re(C₁₄H₁₇N₃O)(CO)₃]Br·CH₄O, has been prepared in almost quantitative yield by reacting (NEt₄)₂[Re(CO)₃Br₃] with the ligand N,N‐bis­picol­yl‐2‐ethano­lamine in refluxing methanol. The X‐ray structure revealed that the Re(CO)₃N₃ coordination sphere is highly distorted from octa­hedral geometry and that the Re(CO)₃ core is facial. The coordinated ligand forms two five‐membered rings, with the pyridine rings in a butterfly formation. The OH group is not involved in metal coordination. The packing of the mol­ecule shows a network of classical O⋯H—O and Br⋯H—O, and non‐classical Br⋯H—C and O⋯H—C hydrogen bonds between the methanol solvate mol­ecules, the metal complex cations and the bromide anions.     

C[triple‐bond]C—H systems as hydrogen‐bond donors and acceptors: trans‐1,2‐diethynylcyclo­hexane‐1,2‐diol and trans‐1,4‐diprop‐2‐ynylcyclo­hexane‐1,4‐diol monohydrate

The title 1,2‐diol derivative, C₁₀H₁₂O₂, crystallizes with two independent but closely similar mol­ecules in the asymmetric unit. Only two of the four OH groups are involved in classical hydrogen bonding; the mol­ecules thereby associate to form chains parallel to the short c axis. The other two OH groups are involved in O—H⋯(C[triple‐bond]C) systems. Additionally, three of the four C[triple‐bond]C—H groups act as donors in C—H⋯O inter­actions. The 1,4‐diol derivative crystallizes with two independent half‐mol­ecules of the diol (each associated with an inversion centre) and one water mol­ecule in the asymmetric unit, C₁₂H₁₆O₂·H₂O. Both OH groups and one water H atom act as classical hydrogen‐bond donors, leading to layers parallel to the ac plane. The second water H atom is involved in a three‐centre contact to two C[triple‐bond]C bonds. One acetyl­enic H atom makes a very short `weak' hydrogen bond to a hydr­oxy O atom, and the other is part of a three‐centre system in which the acceptors are a hydroxy O atom and a C[triple‐bond]C bond.     

Three isomeric forms of hydroxyphenyl‐2‐oxazoline: 2‐(2‐hydroxyphenyl)‐2‐oxazoline, 2‐(3‐hydroxyphenyl)‐2‐oxazoline and 2‐(4‐hydroxyphenyl)‐2‐oxazoline

Crystal structures are reported for three isomeric compounds, namely 2‐(2‐hydroxy­phenyl)‐2‐oxazoline, (I), 2‐(3‐hydroxy­phenyl)‐2‐oxazoline, (II), and 2‐(4‐hydroxy­phenyl)‐2‐oxazoline, (III), all C₉H₉NO₂ [systematic names: 2‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (I), 3‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (II), and 4‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (III)]. In these compounds, the deviation from coplanarity of the oxazoline and benzene rings is dependent on the position of the hydroxy group on the benzene ring. The coplanar arrangement in (I) is stabilized by a strong intra­molecular O—H⋯N hydrogen bond. Surprisingly, the 2‐oxazoline ring in mol­ecule B of (II) adopts a ³T₄ (^C2T_C3) conformation, while the 2‐oxazoline ring in mol­ecule A, as well as that in (I) and (III), is nearly planar, as expected. Tetra­mers of mol­ecules of (II) are formed and they are bound together via weak C—H⋯N hydrogen bonds. In (III), strong inter­molecular O—H⋯N hydrogen bonds and weak intra­molecular C—H⋯O hydrogen bonds lead to the formation of an infinite chain of mol­ecules perpendicular to the b direction. This paper also reports a theoretical investigation of hydrogen bonds, based on density functional theory (DFT) employing periodic boundary conditions.     

1‐Phenyl‐5‐(piperidino­methyl)‐1H‐tetrazole

In the mol­ecule of the title 1,5‐disubstituted tetrazole, C₁₃H₁₇N₅, the tetrazole and benzene rings are not coplanar, having a dihedral angle of 42.96 (5)° between them. The piperidine fragment adopts a chair conformation, and there is a non‐classical intramolecular contact between the benzene H atom and the piperidine N atom. Intermolecular C—H⋯π interactions involving the piperidine C—H groups and the benzene rings are responsible for the formation of two‐dimensional networks, extending parallel to the ab plane. These networks are linked together into a three‐dimensional polymeric structure viaπ–π stacking interactions between the tetrazole rings of two adjacent mol­ecules.     

Chloro­(μ‐6‐methyl­pyridine‐2‐carboxyl­ato)bis­(6‐methyl­pyridine‐2‐carboxyl­ato)triphenyl­chromium(III)­tin(IV) chloro­triphenyl­tin(IV)

The title compound, [CrSn(C₆H₅)₃(C₇H₆NO₂)₃Cl][Sn(C₆H₅)₃Cl(CH₄O)], was obtained from the reaction of Ph₃SnCl with the complex [Cr(C₇H₆NO₂)₃] in methanol. The structure contains [Ph₃SnCl(MeOH)] (A) and [Ph₃SnClCr(C₇H₆NO₂)₃] (B) mol­ecules. In mol­ecule A, the Sn atom of Ph₃SnCl is coordinated by one methanol mol­ecule. In mol­ecule B, the Sn atom of Ph₃SnCl is coordinated by one carboxyl­ate O atom of [Cr(C₇H₆NO₂)₃]. Mol­ecules A and B are connected through an O—H⋯O hydrogen bond between a carboxyl­ate O atom and the methanol OH group. Weak C—H⋯Cl inter­actions and O—H⋯O hydrogen bonds extend the components of (I) into a two‐dimensional network.     

Moxifloxacinium chloride–water–methanol (2/1/1), a novel anti­bacterial agent

Moxifloxacin, a novel fluoro­quinolone with a broad spectrum of anti­bacterial activity, is available as the solvated monohydro­chloride salt 7‐[(S,S)‐2‐aza‐8‐azoniabicyclo­[4.3.0]non‐8‐yl]‐1‐cyclo­propyl‐6‐fluoro‐8‐meth­oxy‐4‐oxo‐1,4‐dihydroquinoline‐3‐carboxylic acid chloride–water–methanol (2/1/1), C₂₁H₂₅FN₃O₄⁺·Cl⁻·0.5H₂O·0.5CH₃OH. The asymmetric unit contains two cations, two chloride ions, a mol­ecule of water and one methanol mol­ecule. The two cations adopt conformations that differ by an almost 180° rotation with respect to the piperidinopyrrolidine side chain. The cyclo­propyl ring and the meth­oxy group are not coplanar with the quinoline ring system. The carboxylic acid function, the protonated terminal piperidyl N atom, the water mol­ecule, the chloride ion and the methanol mol­ecule participate in O—H⋯O, O—H⋯Cl, N—H⋯O and N—H⋯Cl hydrogen bonding, linking the mol­ecules into extended two‐dimensional networks.     

Bis[1,1‐di­methyl­biguanide(1–)‐κ2N2,N5]copper(II) monohydrate

The crystal structure of the title compound, [Cu(C₄H₁₀N₅)₂]·H₂O, contains two independent copper N,N‐di­methyl­biguanide complex units, each with square‐planar coordination of the Cu atom by four N atoms. The two complexes have different symmetry, with one Cu atom lying on an inversion centre and the other on a twofold rotation axis. The Cu—N bond lengths are 1.923 (2) and 1.950 (2) Å in the centrosymmetric complex, and 1.928 (2) and 1.938 (2) Å in the non‐centrosymmetric complex. The crystal structure is stabilized by N—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds; each water mol­ecule forms four hydrogen bonds involving three different Cu complexes.     

Bis(μ‐acetato)(μ‐2,6‐bis­{[(2‐hydroxy­ethyl)(2‐pyridylmeth­yl)amino]meth­yl}‐4‐methyl­phenolato)dinickel(II) hexa­fluoro­phosphate hemihydrate

The asymmetric unit of the title compound, [Ni₂(C₂₅H₃₁N₄O₃)(C₂H₃O₂)₂]PF₆·0.5H₂O, consists of two dinuclear nickel cations, two hexa­fluoro­phosphate anions and one water mol­ecule of crystallization. Within each cation, the Ni atoms are bridged by two exogenous acetate groups and an endogenous cresol O atom of a phenolate‐based `end‐off' compartmental ligand that possesses two pendant chelating arms attached to the ortho positions of the phenol ring. Each Ni atom is six‐coordinate with a slightly distorted octa­hedral geometry. The two symmetry‐independent cations are linked into a dimeric unit through O—H⋯O hydrogen bonds. Additional O—H⋯O, C—H⋯F and C—H⋯O inter­molecular inter­actions link all of the units in the structure into a three‐dimensional framework.     

ap‐9‐(o‐Methyl­phenyl)‐9‐fluorenol,a structure exhibiting several aryl‐H⋯π(arene) intermolecular interactions

The title compound, C₂₀H₁₆O, (I), which crystallized exclusively as its ap rotamer, exhibits several intermolecular aryl‐H⋯π(arene) interactions, resulting in planar molecular arrays in which each mol­ecule interacts with six adjacent mol­ecules. Surprisingly, there were no O—H⋯O—H or O—H⋯π(arene) interactions within hydrogen‐bonding distances. Crystalline (I) melted sharply without molecular decomposition (NMR), but the cooled melt recrystallized only after several hours.     

(−)‐3,7‐Dioxo‐5β‐cholanic acid: dual hydrogen‐bonding modes in a diketonic bile‐acid derivative

The asymmetric unit of the title compound, C₂₄H₃₆O₄, contains three mol­ecules, all differing in their side‐chain conformations and all linked by hydrogen bonding confined entirely within a three‐mol­ecule block. One connection is of the acid‐to‐ketone type [O⋯O = 2.7055 (19) Å and O—H⋯O = 180°] and the other involves carboxyl pairing [O⋯O = 2.6485 (18) and 2.6598 (18) Å, and O—H⋯O = 168 and 174°]. Numerous inter­molecular C—H⋯O close contacts connect neighbouring mol­ecules.