Unusual centrosymmetric structure of [M(18-crown-6)]⁺(M= Rb, Cs and NH₄) complexes stabilized in an environment of hexachloridoantimonate(V) anions

Abstract

In (1,4,7,10,13,16-hexaoxacyclooctadecane)rubidium hexachloridoantimonate(V), [Rb(C12H24O6)][SbCl6], (1), and its isomorphous caesium {(1,4,7,10,13,16-hexaoxacyclooctadecane)caesium hexachloridoantimonate(V), [Cs(C12H24O6)][SbCl6]}, (2), and ammonium {ammonium hexachloridoantimonate(V)-1,4,7,10,13,16-hexaoxacyclooctadecane (1/1), (NH4)[SbCl6]·C12H24O6}, (3), analogues, the hexachloridoantimonate(V) anions and 18-crown-6 molecules reside across -3 axes passing through the Sb atoms and the centroids of the 18-crown-6 groups, both of which coincide with centres of inversion. The Rb(+) [in (1)], Cs(+) [in (2)] and NH4(+) [in (3)] cations are situated inside the cavity of the 18-crown-6 ring; they are situated on -3 axes and are equally disordered about centres of inversion, deviating from the centroid of the 18-crown-6 molecule by 0.4808 (13), 0.9344 (7) and 0.515 (8) Å, respectively. Interaction of the ammonium cation and the 18-crown-6 group is supported by three equivalent hydrogen bonds [N...O = 2.928 (3) Å and N-H...O = 162°]. The centrosymmetric structure of [Cs(18-crown-6)](+), with the large Cs(+) cation approaching the centre of the ligand cavity, is unprecedented and accompanied by unusually short Cs-O bonds [2.939 (2) and 3.091 (2) Å]. For all three compounds, the [M(18-crown-6)](+) cations and [SbCl6](-) anions afford linear stacks along the c axis, with the cationic complexes embedded between pairs of inversion-related anions.

Identification of Singlet Self-Trapped Excitons in a New Family of White-Light-Emitting Zero-Dimensional Compounds

“…It is noted that the distance between two nearest neighboring SbCl 5 2– pyramids is 10.3 Å, which is the longest among all antimony-containing 0D emitters. − DMF molecules are present in the voids, assisting to stabilize the 0D structure. The NH 4 + ions are approximately 0.5 Å off the 18-crown-6 plane, likely due to the size mismatch. , The composition of compound 1 was further verified by thermogravimetric analysis (TGA, Figure S1) and X-ray photoelectron spectroscopy (XPS, Figure S2). The powder XRD pattern (Figure S3) reveals that compound 1 can be obtained in large quantities by using a rapid precipitation approach.…”

Hybrid Disila-Crown Ethers as Hosts for Ammonium Cations: The O–Si–Si–O Linkage as an Acceptor for Hydrogen Bonding

“…, and many more [24][25][26][27][28][29][30][31][32][33]. In the case of hybrid crownethers, aqueous solutions and traces of moisture lead to the entire decomposition of the ligand.…”

Attractive and repulsive forces in a crystal of [Rb(18-crown-6)][SbCl6] under high pressure

“…The [Rb(18-crown-6)][SbCl 6 ] complex was synthesized and crystallized from dimethylformamide following the literature method (Ponomarova et al, 2015). Before the high-pressure (HP) experiments, several crystals of the material were tested on the diffractometer for the best quality diffraction criteria with sharp spots at the highest diffraction angles.…”

“…À (Manskaya et al, 1998), SbCl 6 À (Ponomarova et al, 2015) and hydrogen oximate (Domasevitch et al, 1996)]; (ii) it resides between two large planar moieties (Spisak et al, 2011;Zabula et al, 2014;Rusanova et al, 2000); (iii) in the crystal partial isomorphic substitution in mixed-metal K + /Rb + systems is observed (Wallach et al, 2020).…”

“…In the present work, we explore this new attractive possibility with a closer look at the previously reported )][SbCl 6 ] complex (Ponomarova et al, 2015), which was selected for a range of particular features. Within the one-dimensional cation-anion chains, the [Rb(18-crown-6)] + moieties are centrosymmetric, with the Rb + ion equally disordered over two positions around the center of 18-crown-6 at a relatively small distance of about 0.5 A ˚.…”