Tris(ethyl­ene­diamine)­nickel(II) bis­[2‐cyano‐2‐(oxidoimino)­acetamidato]­nickelate(II) monohydrate

The title compound, [Ni(C₂H₈N₂)₃][Ni(C₃HN₃O₂)₂]·H₂O, appears to be a modular associate consisting of two complex counter‐ions, containing bivalent nickel as the central atom in both cases, and a solvent water mol­ecule. The Ni^II ion in the complex cation lies on the C₂ crystallographic axis. Its coordination environment is formed by six N atoms of three ethyl­ene­diamine (en) mol­ecules, representing a distorted octa­hedral geometry. The Ni^II ion in the complex anion occupies a position at the center of inversion. It exhibits a distorted square‐planar coordination geometry formed by four N atoms belonging to the deprotonated oxidoimine and amide groups of the two doubly charged 2‐cyano‐2‐(oxidoimino)acetamidate anions, situated in trans positions with respect to each other. In the crystal packing, the complex anions are linked by water mol­ecules via hydrogen bonds between the amide O atoms and water H atoms, forming chains translated along the a direction. The [Ni(en)₃]²⁺ cations fill empty spaces between the translational chains, connecting them by hydrogen bonds between the oxime and amide O atoms of the anions and the amine H atoms of the cations, forming layers along the ac plane. The water mol­ecules provide connection between layers through N atoms of the cations, thus forming a three‐dimensional modular structure.     

N‐(3H‐Thia­zol‐2‐yl­idene)­nitr­amine and N‐methyl‐N‐(thia­zol‐2‐yl)­nitr­amine

The geometries of the thia­zole ring and the nitr­amino groups in N‐(3H‐thia­zol‐2‐yl­idene)­nitr­amine, C₃H₃N₃O₂S, (I), and N‐­methyl‐N‐(thia­zol‐2‐yl)­nitr­amine, C₄H₅N₃O₂S, (II), are very similar. The nitr­amine group in (II) is planar and twisted along the C—N bond with respect to the thia­zole ring. In both structures, the asymmetric unit includes two practically equal mol­ecules. In (I), the mol­ecules are arranged in layers connected to each other by N—H⋯N and much weaker C—H⋯O hydrogen bonds. In the crystal structure of (II), the mol­ecules are arranged in layers bound to each other by both weak C—H⋯O hydrogen bonds and S⋯O dipolar interactions.     

tert‐Butyl (3S,6R,9R)‐(5‐oxo‐3‐{[1(R)‐phenyl­ethyl]­carbamoyl}‐1,2,3,5,6,7,8,8a‐octa­hydro­indolizin‐6‐yl)­carbamate monohydrate at 95 K

The asymmetric unit of the title compound, C₂₂H₃₁N₃O₄·H₂O, incorporates one water mol­ecule, which is hydrogen bonded to the 3‐oxo O atom of the indolizidinone system. The two rings of the peptidomimetic mol­ecule are trans‐fused, with the six‐membered ring having a slightly distorted half‐chair conformation and the five‐membered ring having a perfect envelope conformation. The structure is stabilized by intermolecular O—H?O interactions between the water and adjacent peptide mol­ecules, and by N—H?O interactions between the peptide mol­ecules, which link the mol­ecules into infinite chains.     

N‐Benzyl‐2,5‐bis(2‐thienyl)­pyrrole

The solid‐state structure of the title compound, C₁₉H₁₅NS₂, is unusual among substituted thiophene/pyrrole derivatives in that the molecular packing is dominated by π–π interactions between the benzyl substituents. This may be due to the large torsion angles observed between adjacent heterocycles. Torsion angles between adjacent rings in poly­pyrrole and poly­thio­phene conducting polymers are related to conjugation length and the conductivity properties of the polymer materials. The title compound crystallizes in space group P2₁/c with two mol­ecules in the asymmetric unit, both of which exhibit disorder in one of their thio­phene rings.     

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)°.     

4‐Acetamido‐3,3,5,5‐[2H4]‐2,2,6,6‐tetra­([2H3]methyl)piperidin‐1‐yloxyl 0.33‐hydrate

The asymmetric unit of the title compound, C₁₁H₅D₁₆N₂O₂·0.33H₂O, is formed by three crystallographically independent piperidin‐1‐yloxyl mol­ecules and a mol­ecule of water. The mol­ecules are crosslinked by nine hydrogen bonds into layers parallel with the ac plane. The water mol­ecule contributes to the stability of the low‐symmetry arrangement by four hydrogen bonds.     

trans‐Bis­[N‐(2‐hydroxy­ethyl)­ethyl­ene­di­amine‐κ2N,N′]­bis­(iso­thio­cyanato‐κN)­nickel(II)

The crystal structure of the title compound, [Ni(NCS)₂(C₄H₁₂N₂O)₂], has two crystallographically independent half‐mol­ecules in the asymmetric unit, with each Ni atom residing on a centre of symmetry. The two mol­ecules exhibit similar coordination geometry but display differences with regard to other structural features. Each Ni^II centre is octahedrally coordinated by two mutually trans chelating hydroxy­ethyl­ethyl­ene­di­amine ligands and two mutually trans iso­thio­cyanate ions. The two independent mol­ecules form chains through different types of non‐covalent interactions. In the case of one of the mol­ecules, only NCS and free OH groups participate in hydrogen bonding, while in the chain based on the second mol­ecule, the NCS, NH, NH₂ and free OH groups are involved in intermolecular hydrogen bonding. The two chains interact with one another through hydrogen bonding, forming planar sheets. The third packing direction is mediated only by van der Waals interactions.     

6‐(2‐Chloro­acetamido)­hexa­noic acid

Crystals of the title compound, C₈H₁₄ClNO₃, belong to the space group Cc and are characterized by an asymmetric unit containing two mol­ecules, both with a twisted conformation. The mol­ecular packing is stabilized by N—H⋯O=C hydrogen bonds between the amide groups of mol­ecules with the same conformation. In addition, hydrogen‐bonded cyclic carboxylic acid dimers are established between mol­ecules with a different conformation. The ClCH₂—CONH bond has a cis conformation in order to favour an intra­molecular Cl⋯HN electrostatic inter­action. Weak intra‐ and inter­molecular CH₂⋯O=C inter­actions are also present.     

3‐Hydro­xy‐6‐[(4‐hydroxy­phenyl­amino)­methyl­ene]­cyclo­hexa‐2,4‐dienone and 2‐hydroxy‐6‐[(4‐hydroxy­phenyl­amino)­methyl­ene]­cyclo­hexa‐2,4‐dienone

The title compounds, both C₁₃H₁₁NO₃, exist as the keto–amine tautomers, and the formal hydroxyl H atoms, which display strong intramolecular hydrogen bonds, are located on the N atoms. This is a verification of the preference for the keto–amine tautomeric form in the solid state. The 2‐hydroxy isomer has two independent mol­ecules, with the mol­ecules linked by intramolecular N—H⋯O and O—H⋯O and intermolecular O—H⋯O hydrogen bonds into three‐dimensional networks.     

A simple compound with an ­unexpectedly complex structure: 4‐pyridone 6/5‐hydrate

The crystal structure of the title compound, C₅H₅NO·H₂O, contains five independent mol­ecules of pyridone and six independent water mol­ecules. The space group is P2₁, but four of the pyridones and four waters correspond closely to P2₁/n. The packing involves two layers; one consists of head‐to‐tail chains of pyridone mol­ecules 1–4 linked by N—H?O hydrogen bonds, and a second layer involves all the waters and the fifth pyridone. The layers are linked by hydrogen bonds from water to pyridone oxy­gen. The four water O atoms that accept only one classical hydrogen bond have their environment completed by C—H?O interactions.     

Diaqua­malonato(1,10‐phenanthro­line)­zinc(II)

In the crystal structure of the title complex, [Zn(C₃H₂O₄)(C₁₂H₈N₂)(H₂O)₂], the Zn^II atom displays a distorted octa­hedral geometry, being coordinated by two N atoms from the 1,10‐phenanthroline ligand, two O atoms from different carboxyl­ate groups of the chelating malonate dianion and two O atoms of cis water mol­ecules. The complex mol­ecules are linked to form a three‐dimensional supramolecular array by both hydrogen‐bonding inter­actions between coordinated water molecules and the uncoordinated carboxyl­ate O atoms of neighboring mol­ecules, and aromatic π–π stacking inter­actions between neighboring phenanthroline rings.     

Two hydrates of 2,6‐bis­(1H‐benzimidazol‐2‐yl)­pyridine

The structures of the mono‐ and sesquihydrates of 2,6‐bis(1H‐benz­imi­da­zol‐2‐yl)­pyridine (bbip) are reported. Phase (I), C₁₉H₁₃N₅·H₂O, has one water and one bbip mol­ecule in the asymmetric unit, while phase (II), C₁₉H₁₃N₅·1.5H₂O, has three water mol­ecules and two bbip mol­ecules in the asymmetric unit. The compounds exhibit very similar molecular geom­etries but different packing organizations, which result from intricate hydrogen‐bonding schemes.     

Ethyl N‐[2‐(hydroxy­acetyl)­phenyl]­carbamate,ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]­carbamate and ethyl N‐[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]­carbamate

In ethyl N‐[2‐(hydroxy­acetyl)phenyl]carbamate, C₁₁H₁₃NO₄, all of the non‐H atoms lie on a mirror plane in the space group Pnma; the mol­ecules are linked into simple chains by a single C—H⋯O hydrogen bond. The mol­ecules of ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]carbamate, C₁₁H₁₂INO₄, are linked into sheets by a combination of O—H⋯I and C—H⋯O hydrogen bonds and a dipolar I⋯O contact. Ethyl N‐­[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]carbamate, C₁₂H₁₅NO₄, crystallizes with Z′ = 2 in the space group P; pairs of mol­ecules are weakly linked by an O—H⋯O hydrogen bond and these aggregates are linked into chains by two independent aromatic π–π stacking inter­actions.     

A new estra‐1,3,5(10)‐triene‐3,17β‐diol solvate: estradiol–methanol–water (3/2/1)

The title solvate of the steroid 17β‐estradiol (E₂) with methanol and water, C₁₈H₂₄O₂·0.67CH₄O·0.33H₂O, is the first E₂ derivative to contain three crystallographically independent mol­ecules in the asymmetric unit. The three steroid mol­ecules, along with two methanol mol­ecules and a water mol­ecule, create a three‐dimensional hydrogen‐bonded system. Three‐sided columns are formed, with the estradiol mol­ecules aligned lengthwise parallel to (101), and joined by solvent mol­ecules at both hydro­philic ends. The three estradiol mol­ecules differ slightly in their ring‐bowing angles, i.e. the angle between the mean plane of the A ring and that of the BCD ring; this angle ranges from 7.1 to 12.2°.     

3,4‐Di­hydro‐6‐methyl‐3‐β‐d‐ribo­furan­osyl‐4,5′‐cyclo‐9H‐imidazo[1,2‐a]­purin‐9‐one hydrate

In the title compound, C₁₃H₁₃N₅O₄·H₂O (4,5′‐cyclo­wyosine·H₂O), the cyclization forces a syn arrangement of the aglycon with respect to the sugar moiety. The ribo­furan­ose part of the mol­ecule displays a β‐d configuration with an envelope C1′‐endo pucker. The mol­ecules are arranged in columns along the short a axis and are linked to water mol­ecules through O—H?O and O—H?N hydrogen bonds.     

Di­aqua(2,2′‐bi­pyridine)­malonato­manganese(II)

In the crystal structure of the title compound, [Mn(C₃H₂O₄)(C₁₀H₈N₂)(H₂O)₂], the Mn^II atom demonstrates a distorted octahedral geometry, being coordinated by two N atoms of a 2,2′‐bi­pyridine ligand, two O atoms from the carboxyl­ate groups of the chelating malonate dianion and two O atoms of two cis water mol­ecules. The complex mol­ecules are linked to form a three‐dimensional supramolecular array by both hydrogen‐bonding interactions between coordinated water and the carboxyl­ate groups of neighboring mol­ecules and aromatic π–π‐stacking interactions of the bi­pyridine rings.     

Two rhod­amine derivatives: 9‐[2‐(ethoxycarbonyl)phenyl]‐3,6‐bis(ethyl­amino)‐2,7‐di­methyl­xanthyl­ium chloride monohydrate and 3,6‐di­amino‐9‐[2‐(methoxy­carbonyl)­phenyl]xanthyl­ium chloride trihydrate

The title compounds, C₂₈H₃₁N₂O₃⁺·Cl^?·H₂O (common name rhod­amine‐6g), (I), and C₂₁H₁₇N₂O₃⁺·Cl^?·3H₂O (common name rhod­amine‐123), (II), both have planar xanthene skeletons with a formal +1 charge on the amino N atoms delocalized through the π‐electron system so that the N—Csp² bond distances indicate significant double‐bond character. The substituted planar phenyl groups make angles of 63.29 (8) and 87.96 (11)° with the xanthene planes in (I) and (II), respectively. In both mol­ecules, the carbonyl bond vectors point toward the xanthene rings. The ethyl­amine groups in (I) are oriented similarly with their CH₂–CH₃ bond vectors pointing nearly perpendicular to the xanthene plane. The chloride ions and water mol­ecules are disordered in both structures. In (I), the chloride ion and water mol­ecule are disordered between two sites. One water and chloride alternately occupy the same site with occupancy factors of 0.5. The other 0.5‐chloride and 0.5‐water occupy two distinct positions separated by 0.747 (8) Å. In (II), the chloride ion is disordered between three sites and one of the waters is disordered about two other sites. Both crystal structures are stabilized by hydrogen bonds involving the chloride ions, amino groups and water mol­ecules, as well as by π–π stacking between xanthene planes.     

4‐[Bis(1,5‐dimethyl‐1H‐pyrazol‐3‐yl­meth­yl)­amino]phenol monohydrate

The crystal structure of the title compound, C₁₈H₂₃N₅O·H₂O, shows mol­ecules containing a phenol group linked perpendicularly to a roughly planar fragment comprising two pyrazole rings. Mol­ecules are stacked perpendicular to the [101] direction, with their phenol groups disposed alternately. The mol­ecular packing in the crystal is stabilized by hydrogen bonding involving water mol­ecules.     

Hierarchy of hydrogen bonding in bis­(1,4,7‐trioxa‐10‐azoniacyclo­dodecane) bis­(4‐amino­benzoate) trihydrate

In the title compound, 2C₈H₁₈NO₃⁺·2C₇H₆NO₂⁻·3H₂O, proton transfer occurs from the carboxylic acid group of the 4‐amino­benzoic acid (PABA) mol­ecule to the amine group of the macrocycle, resulting in the formation of a salt‐like adduct. The anions are combined into helical chains which are further bound by the water mol­ecules into sheets. The macrocyclic cations are situated between these layers and are bound to the anions both directly and via bridging water mol­ecules. The structure exhibits a diverse system of hydrogen bonding.     

N‐Cyclo­hexyl‐2‐[5‐(4‐pyridyl)‐4‐(p‐tolyl)‐4H‐1,2,4‐triazol‐3‐yl­sulfanyl]­acetamide dihydrate

In the title compound, C₂₂H₂₅N₅OS·2H₂O, the mol­ecules are stacked in columns running along the b axis. In this arrangemant, the mol­ecules are linked to each other by a combination of one two‐centre N—H⋯O hydrogen bond and four two‐centre O—H⋯O hydrogen bonds containing two types of ring motif, viz.R₄⁴(10) and R₃³(11). In the crystal structure, centrosymmetric π–π inter­actions between the triazole rings, with a distance of 3.691 (2) Å between the ring centroids, also affect the packing of the mol­ecules.