Sains Malaysiana 37(2): 195-199(2008)
Synthesis and Characterisation of Tetraalkylammonium Tetrathiotungstate Complexes: X-ray Crystal Structure of Tetrapropylammonium Tetrathiotungstate, [{(C3H7)4N}2WS4] Struktur Kristalografi Sinar-X bagi Tetrapropilamonium Tetratiotungstat, [{(C3H7)4N}2WS4] )
Fadhli Hadana Rahman, Khuzaimah, Rusli Daik & Mohammad B. Kassim School of Chemical Sciences and Food Technology Faculty of Science and Technology, Universiti Kebangsaan Malaysia 43600 UKM Bangi, Selangor, Malaysia
Wan Ramli Wan Daud Department of Chemical and Process Engineering Faculty of Engineering, Universiti Kebangsaan Malaysia 43600 UKM Bangi, Selangor, Malaysia
Diserahkan: 4 April 2007 / Diterima: 15 July 2007
ABSTRACT
The metathesis reaction of aqueous solutions of tetraethylammonium chloride [(C2H5)4NCl], tetrapropylammonium bromide [(C3H7)4NBr] and tetrabutylammonium iodide [(C4H9)4NI] with ammonium tetrathiotungstate in the absence of oxidizing agent afforded the mononuclear tetraethylammonium tetrathiotungstate [{(C2H5)4N}2WS4] (1), tetrapropylammonium tetrathiotungstate [{(C3H7)4N}2WS4] (2) and tetrabutylammonium tetrathiotungstate [{(C4H9)4N}2WS4] (3). Yields obtained for the complexes were 17, 21 and 14 % respectively. The characteristic of W-S stretching mode was detected at 451, 448, 453 cm-1 for 1, 2 and 3. UV-Vis spectra showed three peaks for each complex. The complex 2 has been crystallographically and spectroscopically characterized. The crystal adopted a monoclinic system with a = 15.4246(2) Å, b = 29.7390(1) Å, c = 16.5056(2) Å and β = 114.11° and belong to the P2(1)/n space group. The crystal structure showed a highly disordered tetrapropylammonium molecule involving the position of the C and N atoms. Complexes 1 and 3 were not characterized crystallographically due to its difficulty to form a single crystal.
Keywords: photocatalyst; hydrogen; photolysis; tungsten; tris(dithiolene)
ABSTRAK
Tindak balas metatesis larutan akueus tetraetilamonium klorida [(C2H5)4NCl], tetrapropilamonium bromida [(C3H7)4NBr] dan tetrabutilamonium iodida [(C4H9)4NI] dengan amonium tetratiotungstat tanpa kehadiran agen pengoksida telah menghasilkan tetraetilamonium tetratiotungstat [{(C2H5)4N}2WS4] (1), tetrapropilamonium tetratiotungstat [{(C3H7)4N}2WS4] (2) dan tetrabutilamonium tetratiotungstat [{(C4H9)4N}2WS4] (3). Peratus hasil kompleks yang diperoleh ialah masing-masing 17, 21 dan 14 %. Spektrum inframerah kompleks yang diperoleh menunujukkan ciri regangan W-S masing-masing pada 451, 448, 453 cm-1. Manakala, spektra UV-Vis menunjukkan 3 puncak serapan yang menjadi ciri utama spektra kompleks tetrahedron. Struktur kristalografi sinar-X kompleks 2 menunjukkan hablur mempunyai sistem monoklinik dengan a = 15.4246(2) Å, b = 29.7390(1) Å, c = 16.5056(2) Å dan β = 114.11° dan tergolong di dalam kumpulan ruang P2(1)/n. Struktur yang diperoleh menunjukkan molekul tetrapropilamonium mengalami pengherotan yang melibatkan kedudukan atom C dan N pada salah satu molekul kompleks tersebut. Usaha untuk medapatkan struktur X-ray bagi kompleks 1 dan 3 tidak berhasil kerana sukar untuk mendapatkan hablur yang sesuai.
Kata kunci: fotomangkin; hidrogen; fotolisis; tungsten; tris(dithiolena)
RUJUKAN/REFERENCES
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