Eu₆Sb₆S₁₇ is isotypic with Sr₆Sb₆S₁₇ and can be regarded as consisting of two isolated [Sb₃S₇]^5- anions and an S₃^2- polysulfide anion that are joined together by Eu²⁺ cations. There are six crystallographically unique Eu²⁺ cations bound by sulfide and polysulfide anions in seven-, eight- and nine-coordinate environments. Each of the [Sb₃S₇]^5- anions consists of a trinuclear assembly of corner-sharing SbS₃ units. The [Sb₃S₇]^5- anions are connected by long (3.1 Å) Sb-S inter­actions, forming one-dimensional ribbons running down the a axis and packed with opposing directions of polarity. The bent S₃^2- anions stack in columns parallel to the a axis, oriented in opposing directions with respect to one another. The overall structure is three-dimensional and has channels running down the a axis to house the stereochemically active lone pair of electrons on the Sb³⁺ centers. The presence of Eu²⁺ is supported by both magnetic measurements and bond-valence calculations.

In the anion of the title compound, (C₆H₁₁N₂)[B₅O₆(OH)₄], both six-membered borate rings adopt a flattened boat conformation with the spiro-B atom and its opposite O atom deviating from the remainders of the rings by 0.261 (3)/0.101 (2) and 0.160 (3)/0.109 (2) Å, respectively. The imidazolium cation also deviates from planarity due to rotation of the ethyl group (as indicated by the C—N—C—C torsion angle) by 71.4 (2)° out of the plane of the heterocycle. In the crystal, the anions are connected in a three-dimensional network through O—HO hydrogen bonds, forming channels along the a-axis direction. The cations are situated in the channels, forming C—HO hydrogen bonds with the anions.

The dinuclear Ag^I phosphine complex [Ag₂(dppp)₂]²⁺ [dppp = 1,3-bis­(di­phenyl­phosphino)­propane] has been crystallized as the BF₄⁻ salt, viz. [Ag₂(C₂₇H₂₆P₂)₂](BF₄)₂, in order to reduce the effects of coordination by the anion. The dimeric complex consists of two-coordinate Ag^I centers bridged by dppp ligands. The P—Ag—P bond angle deviates significantly from linearity, with a value of 159.66 (3)°. The Ag—P bond distances are close to being equal, with values of 2.3935 (7) and 2.4016 (7) Å. The cation has a center of symmetry midway between the two Ag atoms.

An organically templated neptunium(IV) fluoride compound, {(C₂H₁₀N₂)[Np₂F₁₀]}_n, has been synthesized under mild hydro­thermal conditions. The compound crystallizes in the monoclinic space group C2/c (No. 15). The structure consists of NpF₉ tricapped trigonal prisms connected through edge- and corner-sharing to form infinite two-dimensional [Np₂F₁₀]^2- sheets, that are separated by the ethyl­enedi­ammonium dications. The C₂H₁₀N₂²⁺ cations form hydrogen-bonding interactions with the [Np₂F₁₀]^2- layers.

A new hydrated thorium chromate, Th(CrO₄)₂(H₂O), has been synthesized under mild hydro­thermal conditions. The structure consists of ThO₈ dodeca­hedra and ThO₉ tricapped trigonal prisms that are inter­connected by chromate anions into a three-dimensional framework.

A caesium thorium(IV) silicate has been synthesized serendipitously under high-temperature solid-state conditions by the reaction of Th^IV with a fused silica/alumina reaction crucible. The compound crystallizes in the orthorhombic space group Pca2₁. The crystal structure consists of ThO₆ distorted octa­hedra corner-shared with SiO₄ tetra­hedra to form an anionic three-dimensional framework possessing extended channels containing Cs⁺ cations. Cs₂ThSi₆O₁₅ is a phyllosilicate with the same sheet structure as β-K₃NdSi₆O₁₅.