First Characterization of the Ammine−Ammonium Complex [{NH₄(NH₃)₄}₂(μ-NH₃)₂]²⁺ in the Crystal Structure of [NH₄(NH₃)₄][B(C₆H₅)₄]·NH₃ and the [NH₄(NH₃)₄]⁺ Complex in [NH₄(NH₃)₄][Ca(NH₃)₇]As₃S₆·2NH₃ and [NH₄(NH₃

Abstract

The compound [NH4(NH3)4][B(C6H5)4].NH3 (1) was prepared by the reaction of NaB(C(6)H(5))(4) with a proton-charged ion-exchange resin in liquid ammonia. [NH(4)(NH(3))(4)][Ca(NH(3))(7)]As(3)S(6).2NH(3) (2) and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3 (3) were synthesized by reduction of As(4)S(4) with Ca and Ba in liquid ammonia. All ammoniates were characterized by low-temperature single-crystal X-ray structure analysis. They were found to contain the ammine-ammonium complex with the maximal possible number of coordinating ammonia molecules, the [NH4(NH3)4]+ ion. 1 contains a special dimer, the [(NH4(NH3)4)2(mu-NH3)2]2+ ion, which is formed by two[NH4(NH3)4]+ ions linked by two ammonia molecules. The H(3)N-H...N hydrogen bonds in all three compounds range from 1.82 to 2.20 A (DHA = Donor-H... Acceptor angles: 156-178 degrees). In 2 and 3, additional H(2)N-H...S bonds to the thioanions are observed, ranging between 2.49 and 3.00 A (DHA angles: 120-175 degrees). Two parallel phenyl rings of the [B(C(6)H(5))(4)](-) anion in 1 form a pi...pi hydrogen bond (C...C distance, 3.38 A; DHA angles, 82 degrees), leading to a dimeric [B(C6H5)4]2(2-) ion.

Comparison of Model Chemistry and Density Functional Theory Thermochemical Predictions with Experiment for Formation of Ionic Clusters of the Ammonium Cation Complexed with Water and Ammonia; Atmospheric Implications

“…The figures show the values for key atom−atom separation distances and bond angles, for the QCISD/6-311G(d,p) structure computed with the CBS-APNO model chemistry, along with results from the PBE1PBE functional. The NH 4 + structure has near- T d symmetry, the NH 4 + (NH 3 ) structure has near- C 3 v symmetry, the NH 4 + (NH 3 ) 2 structure has near- C 2 v symmetry, the NH 4 + (NH 3 ) 3 structure has near- C 3 v symmetry, and the NH 4 + (NH 3 ) 4 structure has near- T d symmetry, in agreement with previous results. − The NH 4 + (NH 3 ) 4 structure has been observed in an inorganic crystal structure, where the crystal packing results in a roughly tetrahedral symmetry . For the NH 4 + (H 2 O) n clusters, previous supersonic jet expansion experiments and calculations have revealed that because of the strong hydrogen bonding ability of water, structural isomers occur for these clusters starting at n = 4. − Figure shows that the NH 4 + (H 2 O) structure has near- C s symmetry, the NH 4 + (H 2 O) 2 structure has near- C 1 symmetry, the NH 4 + (H 2 O) 3 structure has near- C 3 symmetry, and the NH 4 + (H 2 O) 4 structure has near- T d symmetry.…”

“…Figure 1 shows the computed structures for NH 4 + (NH 3 ) n , and Figure 2 [38][39][40][41] The NH 4 + (NH 3 ) 4 structure has been observed in an inorganic crystal structure, where the crystal packing results in a roughly tetrahedral symmetry. 42 For the NH 4 + (H 2 O) n clusters, previous supersonic jet expansion experiments and calculations have revealed that because of the strong hydrogen bonding ability ) n clusters reveals no significant changes in the basic geometry. These structures are similar to the global minima determined by other workers using correlated optimizations.…”

Dissolving the insoluble: CdF2 and moist ammonia form cadmium(II) difluoride monohydrate—synthesis and crystal structure of [Cd(NH3)6]F2·H2O

“…[6,7]. F-HÁÁÁF [8][9][10][11][12] and N-HÁÁÁN [13][14][15][16] hydrogen bonding is much less investigated, and N-HÁÁÁF hydrogen bondingoutside of modified proteins-is comparatively little (12) 19(1) H(1A) 6c 1,980 (6) 3,350 (7) 768 (14) 31(6) H(1B) 6c 2,840(4) 3,650 (5) 1,488 (14) 30(7) H(1C) 6c 3,660(5) 5,410 (5) 1,018 (14) …”

Review. Solvothermal Synthesis and Structure of Chalcogenidoarsenate Anions

“…The effective [26] [Sr(en) 4 ] 2 (As 3 Se 6 )Cl [29] [Fe(phen) 3 ]As 3 S 6 · dien · 7H 2 O [27], [Mn(dien) 2 ] 3 (As 3 Se 6 ) 2 [30] refs. [13,28] restriction to ψ-AsE 3 (E = S, Se) tetrahedra as the basic building units for the construction of oligomeric and polymeric anions leads to a striking paucity in the number of structural types adopted by the thio-and selenidoarsenates(III) in comparison to the analogous chalcogenidoantimonates(III) [9]. However, in addition to chalcogenidoarsenates(III) containing As-EAs bridges, a variety of compounds containing anions with trivalent arsenic atoms connected by oligochalcogenide ligands E n 2− or directly bonded to one another have been isolated under solvothermal conditions.…”

“…UV/Vis spectroscopic and potentiometric studies [17] have shown that mononuclear AsS 3 3− anions readily condense to corner-bridged dipyramidal As 2 S 5 4− and cyclic tripyramidal As 3 S 6 3− anions, of which the latter species predominate at pH ≤ 11. Both As 2 E 5 4− [24,25] [28], all of which were prepared by oxidation of the respective alkali or alkaline earth metals (K or Ca/Ba) in liquid ammonia. These differing synthesis protocols emphasize the importance of structuredirecting counter cations for the isolation of a particular chalcogenidoarsenate anion and also point to the possible role of redox equilibria in determining the nature of the anionic species, a topic that will be highlighted in the following sections.…”