Hydrothermal Growth of Single Crystals of TMA-CuGS-2, [C₄H₁₂N]₆[(Cu_0.44Ge_0.56S_2.23)₄(Ge₄S₈)₃] and Their Characterization Using Synchrotron/Imaging Plate Data

Abstract

Single crystals of TMA-CuGS-2, [C 4 H 12 N] 6 [(Cu 0.44 Ge 0.56 S 2.23 ) 4 (Ge 4 S 8 ) 3 ], were synthesized hydrothermally, and the structure was determined using data collected from sealed-tube and synchrotron X-ray sources. This compound consists of Ge 4 S 10 4adamantine clusters, corner-sharing with MS x units (M ) Cu, Ge; x ) 3 or 4), forming an open framework with tetramethylammonium cations residing within four intersecting channels. Disorder in the M sites causes the composition of the framework to deviate from the ideal stoichiometry, Ge 0.71 M 0.24 S 2 , realized when M ) Cu and x ) 4. This is consistent with results obtained from electron-probe microanalysis. The structure refinements were carried out in space group I4 h3d with cell parameter a ) 20.629 (1) Å. Fourteen unique weak reflections of the type hhl, 2h + l ) 4n + 2, forbidden in I4 h3d, were detected only in the synchrotron/imaging plate experiment. Trial refinements in space groups R3 and I2 1 3 suggest their origin in either weak ordering or multiple scattering effects. diffraction pattern is similar to that of TMA-CoMnGS-2. 1,7 This compound (Figure 1) crystallizes as a framework consisting of two building units, 4-connected Ge 4 S 10 4adamantine and 3-connected MS 4 (M ) Mn/ Co) clusters. 7 Each Ge 4 S 10 4is corner-sharing only with MS 4 and vice versa, forming a (3,4)-connected open framework. The composition of this framework is 3 × (Ge 4 S 8 ) + 4 × (MS 2.5 ) ) Ge 12 M 4 S 34 , which normalizes to Ge 0.71 M 0.24 S 2 (possible protons attached to the framework are neglected). If TMA-CuGS-2 were isostructural with TMA-MnCoGS-2, the framework should be consistent with this composition. Instead the chemical analysis reported for the CuGS-2 material is Ge 0.89 -Cu 0.11 S 2 . 1 In this paper, we report the hydrothermal synthesis, composition, and structural analysis of TMA-CuGS-2 single crystals. For structural studies, besides conventional single-crystal diffractometry, synchrotron radiation in combination with an imaging plate (IP)

Open-Framework Inorganic Materials

“…They were able to obtain crystals from the diffusion of an aqueous solution of the 3d metal into a solution of an amine ± [Ge 4 [202] or trigonal planar threefold coordination ([CuS 3 ]). [203] An example of metal ± metal linking is found in the mixed silver ± copper germanium sulfide, (CH 3 ) 4 N[(Ag 2 ,Cu 2 )Ge 4 S 10 ]. [204] The open framework is built up from the connection of the [Ge 4 S 10 ] unit by metal ± metal bonds of the type [Ge(m-S)] 2 M-M[Ge(m-S)] 2 (M Cu, Ag).…”

Generation and Trapping Reactions of a Formal 1:1 Complex between Singlet Carbon and 2,2′-Bipyridine

“…[6] Figure 1 shows the result of the X-ray structure analysis of 4-Br´H 2 O. [7] Figure A noticeable feature in the 1 H NMR spectra of 4-Br and 4-OTf is the large 1 H ± 13 C coupling constant (232.59 Hz) for the C À H bond in the five-membered ring. This coupling constant almost corresponds to sp hybridization of the C atom in this bond (the exact value is sp 1.15 ).…”

“…[7] This protein domain possesses a globular structure composed of a three-stranded antiparallel b sheet which positions the flexible N and C termini in close proximity. [8] Given that native chemical ligation is tolerant to the presence of chemical denaturants, [6] it was anticipated that insights into the effect of this juxtaposition on the chemical reaction rate would be forthcoming.…”

Metastructures: homeomorphisms between complex inorganic structures and three-dimensional nets

“…As far as we know, there is no homeomorphism between this net and any structure. (Ziebarth & Corbett, 1987 A (three, four)-connected net is homeomorphic with the recently synthesized structure of TMA-MGS-2, a metal germanium-sul®de compound in which adamantane-shaped [Ge 4 S 6 ] groups are tetrahedrally surrounded by [MS 4 ] groups (M = Cu, Co, Ge, Mn; Bedard et al, 1989;Tan et al, 1996) and the [MS 4 ] groups are three-connected to the adamantane groups. The resulting general formula for the (three, four)-connected -type structure is [GeS 6 ] 3 [MS 4 ] 4 (TMA).…”