Two novel glycine metal halogenides: catena‐poly[[[diaqua­nickel(II)]‐di‐μ‐glycine] dibromide] and catena‐poly[[[tetra­aqua­magnesium(II)]‐μ‐glycine] dichloride]

In catena‐poly[[[diaqua­nickel(II)]‐di‐μ‐glycine] dibromide], {[Ni(C₂H₅NO₂)₂(H₂O)₂]Br₂}_n, (I), the Ni atom is located on an inversion centre. In catena‐poly[[[tetra­aqua­magnesium(II)]‐μ‐glycine] dichloride], {[Mg(C₂H₅NO₂)(H₂O)₄]Cl₂}_n, (II), the Mg atom and the non‐H atoms of the glycine mol­ecule are located on a mirror plane. All other atoms are located on general positions. The atomic arrangements of both compounds are characterized by [MO₆] octa­hedra (M = Ni or Mg) connected by glycine mol­ecules, with the halogenide ions in the inter­stices. In (I), four of the coordinating O atoms are from glycine and two are from water mol­ecules, building layers of octa­hedra and organic mol­ecules. In (II), two of the coordinating O atoms are from glycine and four are from water mol­ecules. The octa­hedra and organic mol­ecules form chains.     

Three novel non‐centrosymmetric compounds of glycine: glycine lithium sulfate,glycine nickel dichloride dihydrate and glycine zinc sulfate trihydrate

The crystal structures of three compounds of glycine and inorganic materials are presented and discussed. The ortho­rhombic structure of glycinesulfatodilithium(I), [Li₂(SO₄)(C₂H₅NO₂)]_n, consists of corrugated sheets of [LiO₄] and [SO₄] tetrahedra. The glycine mol­ecules are located between these sheets. The main features of the monoclinic structure of di­aqua­di­chloro­glycinenickel(II), [NiCl₂(C₂H₅NO₂)(H₂O)₂]_n, are helical chains of [NiO₄Cl₂] octahedra connected by glycine mol­ecules. The orthorhombic structure of tri­aqua­glycinesulfatozinc(II), [Zn(SO₄)(C₂H₅NO₂)(H₂O)₃]_n, is made up of [O₃SOZnO₅] clusters. These clusters are linked by glycine mol­ecules into zigzag chains. All three compounds are examples of non‐centrosymmetric glycine compounds.     

Glycinium oxalate

In the title compound, C₂H₆NO₂⁺·C₂HO₄⁻, the glycine mol­ecule exists in the cationic form and the oxalic acid mol­ecule in the mono-ionized state. The mol­ecules aggregate into alternate columns of glycinium and semi-oxalate ions. The structure is stabilized by an extensive network of hydrogen bonds.     

μ‐Glycine‐O:O′‐di‐μ‐oxo‐bis[(gly­cinato‐N,O)­oxomolybdenum(V)]

In the title compound, [Mo₂O₄(C₂H₄NO₂)₂(C₂H₅NO₂)], two Mo atoms sit in the same distorted pentagonal bipyramid coordination environment. There are four ligand types: oxo‐O, μ₂‐O, μ₂‐glycine and chelate glycine. There is an Mo—Mo bond between the two Mo atoms [2.552 (1) Å]. All amino groups participate in hydrogen bonding with O atoms of other mol­ecules, thus connecting the mol­ecules into a three‐dimensional structure.     

Two new non‐centrosymmetric lithium salts of glycine: bis(glycine) lithium chromate monohydrate and bis(glycine) lithium molybdate

In bis­(glycine) lithium chromate monohydrate {systematic name: poly[aquadi‐μ‐glycinato‐μ‐tetra­oxochromato(VI)‐dilithium(I)]}, [CrLi₂(C₂H₅NO₂)₂O₄(H₂O)]_n, (I) (space group P2₁2₁2₁), and bis­(glycine) lithium molybdate {systematic name: poly[di‐μ‐glycinato‐μ‐tetra­oxomolybdato(VI)‐dilithium(I)]}, [Li₂Mo(C₂H₅NO₂)₂O₄]_n, (II) (space group P2₁), all atoms are located on general positions. The crystal structure of (I) is characterized by infinite chains of corner‐sharing [LiO₄] tetra­hedra, which are connected by glycine mol­ecules to form layers. [CrO₄] tetra­hedra are attached to the [LiO₄] tetra­hedra. Compound (II) contains dimers of [LiO₄] tetra­hedra which are connected by [MoO₄] tetra­hedra to form chains, which are in turn connected by glycine mol­ecules to form double layers.     

[(4,4‐Dimethyl‐2‐oxo‐1,3‐oxazolidin‐3‐yl)methyl]phosphonic acid

The title compound, C₆H₁₂NO₅P, was synthesized as an inter­mediate phase in a search for new N‐(phosphono­methyl)glycine derivatives. The mol­ecules are held together by O—H⋯O hydrogen bonds, forming chains along the b axis in the crystal structure. The observed mol­ecular structure is compared with that calculated by the density functional theory method.     

Secondary interactions in 1‐iodo‐3‐nitrobenzene and 1‐iodo‐3,5‐dinitrobenzene

The crystal packing of 1‐iodo‐3‐nitro­benzene, C₆H₄INO₂, is formed by planar mol­ecules which are linked by I⋯I and NO₂⋯NO₂ interactions. In the case of 1‐iodo‐3,5‐di­nitro­benzene, C₆H₃IN₂O₄, the NO₂ groups are not exactly coplanar with the benzene ring and the mol­ecules form sheets linked by NO₂⋯NO₂ interactions. In contrast with 4‐iodo­nitro­benzene, the crystal structures of both title compounds do not form highly symmetrical I⋯NO₂ intermolecular interactions.     

4-Nitro-9,10-di­hydro­phenanthrene and a polymorphic form of 4-nitro­phenanthrene

The crystal structures of 4-nitro-9,10-di­hydro­phenanthrene, C₁₄H₁₁NO₂, (I), and 4-nitro­phenanthrene, C₁₄H₉NO₂, (II), the latter having two crystallographically independent mol­ecules, show that the mol­ecules are not planar. The dihedral angles between the phenyl rings of the bi­phenyl skeletons are 28.64 (8)° for (I), and 10.34 (15) and 11.75 (13)° for the two mol­ecules of (II). The differences in the dihedral angles have an effect on the photochemical reactivity of the mol­ecules.     

3‐(1‐Pyridinio)propane­sulfonate and 3‐(benzyl­dimethyl­ammonio)propane­sulfonate monohydrate

3‐(1‐Pyridinio)propane­sulfonate, C₈H₁₁NO₃S, and 3‐(benzyl­dimethyl­ammonio)propane­sulfonate monohydrate, C₁₂H₁₉NO₃S·H₂O, used as additives during protein refolding and crystallization, both crystallize in the monoclinic system in the P2₁/c space group, with one mol­ecule (or one set of mol­ecules) per asymmetric unit. The solvent water mol­ecule present in the second crystal structure results in the formation of a dimer through hydrogen bonds. The conformation of the propane­sulfonate moiety is similar in both structures.     

2,6‐Diiodo‐4‐nitrophenol, 2,6‐diiodo‐4‐nitrophenyl acetate and 2,6‐diiodo‐4‐nitroanisole: interplay of hydrogen bonds,iodo–nitro interactions and aromatic π–π‐stacking interactions to give supramolecular structures in one,two and three dimensions

In 2,6‐di­iodo‐4‐nitro­phenol, C₆H₃I₂NO₃, the mol­ecules are linked, by an O—H?O hydrogen bond and two iodo–nitro interactions, into sheets, which are further linked into a three‐dimensional framework by aromatic π–π‐stacking interactions. The mol­ecules of 2,6‐di­iodo‐4‐nitro­phenyl acetate, C₈H₅I₂NO₄, lie across a mirror plane in space group Pnma, with the acetyl group on the mirror, and they are linked by a single iodo–nitro interaction to form isolated sheets. The mol­ecules of 2,6‐di­iodo‐4‐nitro­anisole, C₇H₅I₂NO₃, are linked into isolated chains by a single two‐centre iodo–nitro interaction.     

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.     

Betaine betainium hydrogen oxalate

The title compound, C₅H₁₂NO₂⁺·C₂HO₄⁻·C₅H₁₁NO₂ or HC₂O₄⁻·(HBET·BET)⁺ [BET is tri­methyl­glycine (betaine); IUPAC name: 1-carboxy-N,N,N-tri­methyl­methanaminium hydro­xide inner salt], contains pairs of betaine mol­ecules bridged by an H atom, forming dimers linked by a strong hydrogen bond. The hydrogen oxalate anions have a rather unusual star conformation, with an internal torsion angle of 70.1 (4)°. The betaine–betainium dimers are anchored between two zigzag chains of hydrogen oxalate mol­ecules hydrogen bonded head-to-tail running parallel to the b axis. An extended network of C—H⃛O interactions links the anionic chains to the cationic dimers.     

Cerous sodium nitrate monohydrate,Na2Ce(NO3)5·H2O

The title compound, disodium cerium pentanitrate monohydrate, was synthesized from a nitric acid solution of Ce(NO₃)₃·6H₂O and NaNO₃, and its structure has been determined from single‐crystal X‐ray diffraction data. The structure is built from isolated chains of irregular icosahedral [Ce(NO₃)₆]^3? anions. Na atoms and water mol­ecules are located between the chains. The Na coordination polyhedra, in the form of a square antiprism or a monocapped square antiprism, share common vertices and contribute to the formation of a three‐dimensional network. Ten nitrate groups act as bridging ligands.     

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.     

Copper(II) and zinc(II) complexes of pyridine‐2,6‐di­carboxyl­ic acid

The title compounds, bis­(pyridine‐2,6‐di­carboxyl­ato‐N,O,O′)copper(II) monohydrate, [Cu(C₇H₄NO₄)₂]·H₂O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C₇H₄NO₄)₂]·3H₂O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand mol­ecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand mol­ecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand mol­ecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water mol­ecules.     

Sodium hydrogen nitrilo­tri­acetate dihydrate

In the title compound, Na⁺·C₆H₈NO₆^?·2H₂O, the sodium ion is coordinated in a distorted octahedral manner by two carboxyl­ate O atoms and two water O atoms. Each of these water mol­ecules bridges two adjacent Na ions, resulting in two four‐membered rings of the type Na–O–Na–O.     

A new crystalline phase of nitric acid dihydrate

The crystal structure of a new high-temperature phase of nitric acid dihydrate, HNO₃·2H₂O, has been determined at 225 K by single-crystal X-ray diffraction. The H atom of the nitric acid is delocalized to one water mol­ecule, leading to an association of equimolar NO₃⁻ and H₅O₂⁺ ionic groups. The asymmetric unit contains two mol­ecules of HNO₃·2H₂O. The two independent mol­ecules are related by a pseudo-twofold c axis, by a translation of 0.54 (approximately ½) along b , with a mean atomic distance difference of 0.3 Å, except for one H atom of the water mol­ecules (1.5 Å), because of their different orientations in the two mol­ecules. The two independent mol­ecules, linked by strong hydrogen bonds, are arranged in layers. These layers are linked by weaker hydrogen bonds oriented approximately along the c axis. A three-dimensional hydrogen-bond network is observed.     

Poly[[diaqua­cadmium(II)]‐μ4‐[N‐(phosphonato­methyl)ammonio]acetato]

The title compound, [Cd(C₃H₆NO₅P)(H₂O)₂]_n, is a three‐dimensional polymeric complex. The asymmetric unit contains one Cd atom, one N‐(phosphono­methyl)glycine zwitterion [(O⁻)₂OPCH₂NH₂⁺CH₂COO⁻] and two water mol­ecules. The coordination geometry is a distorted CdO₆ octa­hedron. Each N‐(phosphono­methyl)glycine ligand bridges four adjacent water‐coordinated Cd cations through three phospho­nate O atoms and one carboxyl­ate O atom, like a regular PO₄³⁻ group in zeolite‐type frameworks. One‐dimensional zigzag (–O—P—C—N—C—C—O—Cd–)_n chains along the [101] direction are linked to one another via Cd—O—P bridges and form a three‐dimensional network motif with three types of channel systems. The variety of O—H⋯O and N—H⋯O hydrogen bonds is likely to be responsible for stabilizing the three‐dimensional network structure and preventing guest mol­ecules from entering into the channels.     

Ethyl 2‐benzyl‐2‐nitro‐3‐phenyl­propanoate

The title compound, C₁₈H₁₉NO₄, is the key synthetic intermediate in the preparation of α,α‐di­benzyl‐α‐amino acid (di­benzyl­glycine, Dbg), the disubstituted homologue of phenyl­alanine, following the di­alkyl­ation of ethyl nitro­acetate. The mol­ecule does not have its potential mirror symmetry in the crystal, with the two benzyl groups forming N—C—C—C torsion angles of 60.31 (13) and 79.89 (13)°.     

Gabapentin and gabapentin monohydrate

Gabapentin [1‐(amino­methyl)­cyclo­hexane­acetic acid, C₉H₁₇NO₂] is a zwitterion in the solid state. Its crystal structure involves extensive hydrogen bonding between the NH₃⁺ and COO^? groups of neighboring mol­ecules. The structure of gabapentin monohydrate [1‐(amino­methyl)­cyclo­hexane­acetic acid monohydrate, C₉H₁₇NO₂·H₂O] also involves such hydrogen bonding and, in addition, has a hydrogen‐bonding network comprising the water mol­ecules and both the NH₃⁺ and COO^? groups.