Synthesis and Crystal Structures of Hg6Sb5Br7, Hg6As4BiCl7, and Hg6Sb4BiBr7, Built of a Polycationic Mercury-Pnictide Framework with Trapped Anions

The Synthesis, Crystal and Band Structures, and Properties of the Quaternary Supramolecular Complexes [Hg6Z4](MX6)Hgy (Z = As, Sb; M = Hg, Cd; X = Cl, Br, I; y = 0, 0.5, 0.6)

“…The Hg1–As, Hg1–Sb, and As–As bond lengths in the cationic moieties in the present compounds range from 2.496(2) to 2.531(2), 2.686(2) to 2.693(2), and 2.389(7) to 2.428(6) Å, respectively, all of which lie in the normal ranges for Hg–Z and As–As bond lengths in known mercury pnictide halides 2–6. The Sb–Sb bond length of 2.790(5) Å is also in good agreement with those found in various mercury antimonide halides 3f,6a. The Hg3–Cl [2.70(1) Å] and Cd–X [Cd–Cl 2.636(7), Cd–Br 2.806(3), Cd–I 3.006(2) Å] bond lengths in the guest anions are all close to the those in mercury and cadmium pnictide halides 2e,2f…”

Synthesis, crystal and band structures, and optical properties of a new framework mercury pnictides: [Hg4As2](InBr3.5As0.5) with tridymite topology

“…from 3.81 to 3.87Å, which are much longer than the normal Hg-Br covalent bond distance (2.64Å) and shorter than the sum of van de Waals radii of Hg and Br atoms. Thus, the host-guest supramolecular interactions fix the guest anions to their specific position so that no position or rotational disorder is observed for them, which is also found in the literatures [24][25][26][27][28][32][33][34][35].…”

“…And this results in forming less ordered open-frameworks with lower symmetry among the four reported compounds (space group P 63 /mmc for 1 but P2 1 for them). Therefore, unlike the above two kinds of open-frameworks composed of mercury pnictides reported in the literature [24][25][26][27][28][32][33][34][35], the open-framework composed of AsHg 4 tetrahedra in 1 is a new type of one with a novel tridymite topology. As for the guest anions, it can be regarded as a 1D corner-sharing Br 5 trigonal bipyramidal anionic network with 1/2 Br 5 polyhedra being occupied by In atoms (Fig.…”

“…Till now, two principal types of frameworks can be distinguished. The first type is the topology with the formula of (Hg 6 Z 4 ) 4+ (Z = P, As, Sb) [24][25][26][27][28] possessing cavities of two different sizes in close proximity that are capable of trapping two different types of guests. The second type is the analogues of the well-known Millon's base salts [29][30][31], composed of cationic frameworks with the formula [Hg 4 Z 2 ] 2+ (Z = P, As), which adopt a tridymite-like topology filled with different tetrahedral anions.…”

Polykationische Hg-Pnictid-Gerüste mit einer neuen Füllungsvariante in den Strukturen von Hg3As2TlCl3 und Hg3Sb2TlBr3

“…Vergleich der Strukturen von (Hg 3 Y 2 )TlX 3 mit der kubischen Substanzfamilie (Hg 6 6 ]X [4,5] deutlich. Dies ist auch an den Gitterkonstanten zu erkennen.…”