Golden oldies: ten crystallography articles that we think must be read

We have selected a set of ten diverse crystallography articles to illustrate important moments in the development of our field of science. They are a mixture of `science pull and technology push'. Ten is an arbitrary number and our choice is personal, so many others might have been chosen.

Structure of (R,R)-4-bromo-2-{4-[4-bromo-1-(4-toluene­sulfon­yl)-1H-pyrrol-2-yl]-1,3-di­nitro­butan-2-yl}-1-(4-toluene­sulfon­yl)-1H-pyrrole, another ostensible by-product in the synthesis of geminal-di­methyl hydro­dipyrrins

The crystal structure of a by-product in the synthesis of geminal-dimethyl hydro­dipyrrins is reported; (R,R)-4-bromo-2-{4-[4-bromo-1-(4-toluene­sulfon­yl)-1H-pyrrol-2-yl]-1,3-di­nitro­butan-2-yl}-1-(4-toluene­sulfon­yl)-1H-pyrrole (1, C₂₆H₂₄N₄O₈S₂Br₂). Generated through a nitro­nate-mediated dimerization, this compound presents unforeseen enanti­omeric resolution, something previously not noted in its singular prior report. This crystal adds to the ever-growing library of by-products arising from these syntheses.

Crystal structure and Hirshfeld surface analysis of (1H-imidazole-κN³)[N-(2-oxido­benzyl­idene)tyrosinato-κ³O,N,O′]copper(II)

The amino acid Schiff base copper(II) title complex consists of a tridentate ligand synthesized from L-tyrosine and salicyl­aldehyde. One imidazole mol­ecule is additionally coordinating to the copper(II) ion. The crystal structure features N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds.

Crystal structure of Ag₃Dy₂(NO₃)₉ and qu­anti­tative comparison to isotypic compounds

The crystal structure of the title compound and its particular relation to isotypic compounds is considered.

Synthesis, crystal structure, Hirshfeld surface analysis and DFT study of the 1,1′-(buta-1,3-diyne-1,4-di­yl)bis­(cyclo­hexan-1-ol)

The two crystallographically non-equivalent mol­ecules in the title compound have C₂ and C_i symmetries. The crystal structure features strong inter­mol­ecular O—H⋯O hydrogen bonds, which form eight-membered rings with (8) graph-set motifs, linking the mol­ecules into layers.

Crystal structure and Hirshfeld-surface analysis of a monoclinic polymorph of 2-amino-5-chloro­benzo­phenone oxime at 90 K

The synthesis and crystal structure of a monoclinic polymorph of 2-amino-5-chloro­benzo­phenone oxime, C₁₃H₁₁ClN₂O, are presented along with a comparison to a previously determined triclinic form.

Metal halide coordination compounds with quinazolin-4(3H)-one

The cadmium(II) and mercury (II) coordination compounds with composition [CdBr₂(quinoz)] and [HgCl₂(quinoz)], respectively, where quinoz = quinazolin-4(3H)-one, are chain polymers with bridging halogen atoms. The structure of [CdI₂(quinoz)₂] was re-determined at 100 K, modeling minor disorder.

Crystal structures of two Sm^III complexes with dipicolinate [DPA]²⁻ ligands: comparison of luminescent properties of products obtained at different pH values

Crystallization of the title compounds, synthesized from Sm(CF₃SO₃)₃ and dipicolinic acid solution, was found to change as a function of pH.

Cyclo­penta­dienone triisocyanide iron complexes: general synthesis and crystal structures of tris­(2,6-di­methyl­phenyl isocyanide)(η⁴-tetra­phenyl­cyclo­penta­dienone)iron and tris­(naphthalen-2-yl iso­cyanide)(η⁴-tetra­phenyl­cyclo­penta­dienone)iron acetone hemisolvate

Cyclo­penta­dienone triisocyanide iron complexes were isolated and fully characterized for the first time. Two of the twelve isolated complexes could be crystallographically characterized.

Crystal structure of 1-(4-bromo­phen­yl)but-3-yn-1-one

The title compound crystallizes in the monoclinic crystal system in the centrosymmetric space group P2₁/n. The crystal structure features C—H⋯O hydrogen bonding and a short C=O⋯C≡C (acetyl­ene) contacts.

Crystal structures and Hirshfeld surface analyses of (E)-1-[1-(4-tert-butyl­phen­yl)-2,2-di­chloro­ethen­yl]-2-phenyl­diazene, (E)-1-[1-(4-tert-butyl­phen­yl)-2,2-di­chloro­ethen­yl]-2-(4-methyl­phen­yl)diazene, (E)-1-[1-(4-tert-butyl­phen­yl)-2,2-di­chloro­ethen­yl]-2-(4-meth­oxy­phen­yl)diazene and (E)-1-[1-(4-tert-butyl­phen­yl)-2,2-di­chloro­ethen­yl]-2-(3-methyl­phen­yl)diazene

C—H⋯π and C—Cl⋯π inter­actions are the most important inter­molecular inter­actions in the crystal structures of the title compounds.

Synthesis, crystal structure and Hirshfeld surface analysis of bis­(caffeinium) hexa­chlorido­platinum(IV) in comparison with some related compounds

In the crystal, the cations and anions form a layered structure via strong N—H⋯Cl, weak C—H⋯Cl and C—H⋯O hydrogen bonds and π-stacking inter­actions.

3,5-Lutidine penta­aqua sulfate complexes of first-row transition metals: [M(3,5-lutidine)(H₂O)₅]SO₄, with M = Mn, Co, Ni, and Zn

The structures of four metal 3,5-lutidine penta­aqua sulfates (Mn, Co, Ni, Zn) are presented and are shown to be isostructural.

Crystal structure of 5-(β-D-gluco­pyran­osyl­thio)-N-(4-methyl­phen­yl)-1,3,4-thia­diazol-2-amine

In the title compound, the angle between the tolyl and thia­diazole rings is 9.2 (1)°. The hydrogen bonding is a combination of a ribbon involving hydrogen bonds of the sugar residues, and a layer based on N—H⋯O and O—H⋯N hydrogen bonds.

catena-Poly[[bis­(di­aqua­lithium)]-μ₄-3,3′,5,5′-tetra­nitro-4,4′-bi­pyrazole-1,1′-diido]: a new moisture-insensitive alkali-metal energetic salt with a well-defined network structure

In the title salt, the 3,3′,5,5′-tetra­nitro-4,4′-bi­pyrazole-1,1′-diide dianion [{TNBPz}²⁻] is situated across the twofold axis. The distorted coordination octa­hedra around Li⁺ involve four short bonds with two pyrazolate N atoms and two aqua ligands and two longer contacts with nitro-O atoms. When combined with μ₄-{TNBPz}²⁻, this generates a mono-periodic polymeric structure incorporating discrete centrosymmeric [(H₂O)₂Li–(di­nitro­pyrazolato)₂–Li(H₂O)₂] units. The three-dimensional stack of mutually orthogonal coordination chains is reminiscent of a Lincoln log pattern.

Synthesis, crystal structure and Hirshfeld surface analysis of tert-butyl 4-[4-(di­fluoro­meth­oxy)phen­yl]-2,7,7-tri­methyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxyl­ate

In the crystal, mol­ecules are connected via N—H⋯O and C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming layers parallel to the (100) plane. van der Waals forces and C—H⋯F inter­actions connect these layers, consolidating the crystal structure.

Crystal structure and Hirshfeld surface analysis of bis­{(Z)-N′-[(E)-(furan-2-yl)methyl­idene]carbamo­hydrazono­thio­ato}nickel(II) methanol disolvate

In the title complex, the Ni^II atom is coordinated by the S and N atoms of two N′-[(Z)-(furan-2-yl)methyl­idene]carbamohydrazono­thioic acid ligands in a distorted square-planar geometry.

The synthesis, crystal structure and spectroscopic analysis of (E)-3-(4-chloro­phen­yl)-1-(2,3-di­hydro­benzo[b][1,4]dioxin-6-yl)prop-2-en-1-one

The synthesis, crystal structure and some spectroscopic details for (E)-1-(2,3-di­hydro­benzo[b][1,4]dioxin-6-yl)-3-(4-chloro­phen­yl)prop-2-en-1-one are presented.

Crystallographic and spectroscopic characterization of two 1-phenyl-1H-imidazoles: 4-(1H-imidazol-1-yl)benzaldehyde and 1-(4-meth­oxy­phen­yl)-1H-imidazole

Two 1-phenyl-1H-imidazoles, 4-(1H-imidazol-1-yl)benzaldehyde and 1-(4-meth­oxy­phen­yl)-1H-imidazole, differ in the substituent para to the imidazole group on the arene ring. Both mol­ecules pack with different motifs via similar weak C—H⋯N/O inter­actions and differ with respect to the angles between the mean planes of the imidazole and arene rings.