KAJIAN STRUKTUR DAN DINAMIKA SOLVASI LITIUM(I) DALAM AMONIAK CAIR MENGGUNAKAN SIMULASI DINAMIKA MOLEKULAR QMCF (QUANTUM MECHANICAL CHARGE FIELD)

NIKO PRASETYO, Dr. Ria Armunanto, M.Si.; Prof. Dr. Karna Wijaya, M.Eng.

2015 | Tesis | S2 Ilmu Kimia

Solvasi ion Li+ dalam amoniak cair telah dipelajari menggunakan metode simulasi dinamika molekular (quantum mechanical charge field) QMCF. Ion Li+ disolvasi oleh 4 molekul NH3 secara tetrahedral pada jarak 2,075 Ã… dalam kulit solvasi pertama. Dua usaha pertukaran ligan teramati selama waktu simulasi 12 ps. Kulit solvasi kedua menunjukkan struktur yang lebih labil dengan banyak pertukaran ligan yang sukses. Hasil simulasi menunjukkan kedekatan data dengan hasil eksperimen.

The solvation of Li(I) in liquid ammonia has been investigated by an ab initio quantum mechanical charge-field molecular dynamics (QMCF-MD) simulation. Being the first simulation of a metal cation in liquid ammonia employing this methodology, the work yields a wide range of accurate structural and dynamical data. Li(I) is tetrahedrally coordinated by four ammonia molecules in the first solvation shell at a distance of 2.075 Ã…. Two ligand exchange attempts have been observed within 12 ps of simulation time. The second solvation shell shows a more labile structure with numerous successful exchanges. The results are in excellent agreement with experiments.

Kata Kunci : Li+, amoniak cair, quantum mechanical charge field (QMCF), simulasi dinamika molekular.