摘要
中文摘要 以[PPN][Se2Mn3(CO)9]為起始物與Fe(CO)5依莫耳數1：1.71之比例，於2.5M之KOH溶於等體積的MeOH與CH2Cl2混合溶液中反應，可得缺一電子之三角錐結構產物[PPN]2[SeMnFe2(CO)9](Td)。若鹼性濃度降為0.5M，則產生具八面體結構的[PPN]2[Se2Mn2Fe2(CO)11](Oh)及未知物(A)的混合產物；若將KOH濃度提升為4M，則獲一已知的穩定產物[PPN]2[SeFe3(CO)9]。以相同比例，將起始物的陽離子改為[PPh4]+，並將鹼濃度控制在1M以下反應65小時，即可將Oh產物單離出。於此系統下，將KOH濃度固定於2M，反應 25小時後可得到非常特別的蝴蝶型結構化合物[PPh4]2[SeMn2Fe2(CO)12](Butterfly)，是為一罕見的diradical species，且隨時間增加其會有逐漸轉變為Oh及未知物(A)的傾向。除此，為能進一步了解[Se2Mn3(CO)9]-的反應性，亦與其他氧化劑或還原劑反應，結果則多形成穩定的雙錳化合物。 由於反應性較強的Cr(CO)6在鹼性條件下可引入[Se2Mn3(CO)9]-中，同族的Mo(CO)6卻宣告失敗。故將Mo(CO)6、Mn2(CO)10及SeO2以莫耳比2：1：3之一鍋化方式反應，可成功獲得第一個同時混有m3-O及m3-Se的雙三角錐結構產物[PPN]2[SeOMn3(CO)9]， 乍看之下Mo(CO)6並未參與反應，推測其可能是扮演催化角色，而促使O原子產生並橋接於Mn3金屬平面上。 此外，由於我們研究中所有新化合物其架構電子並不符合電子理論計算，於電子順磁共振光譜(electron paramagnetic resonance；EPR)皆顯現其內含未成對電子，尤其是butterfly結構產物之雙自由基吸收特別明顯，而磁性測量結果則呈反鐵磁現象(antiferromagnetism)。另外，亦進行77Se NMR測定並以電化學探討氧化還原性質。
關鍵字
金屬團簇並列摘要
Abstract The reaction of [PPN][Se2Mn3(CO)9] with Fe(CO)5 in a molar ratio of 1：1.71 in 2.5M KOH in a mixed solutions of MeOH and CH2Cl2 (v：v＝1：1) produces an electron-deficient tetrahedral cluster complex [PPN]2[SeMnFe2(CO)9]. If the concentration of KOH is decreased to 0.5M, the new octahedral compound [PPN]2[Se2Mn2Fe2(CO)11] and unknown(A) are formed together. When the 4M KOH is used, the stable known compound [PPN]2[SeFe3(CO)9] is obtained. The octahedral complex can be isolated by the employment of [PPh4]＋ as the cations and by the control of KOH concentration (＜1M) and the reaction time (65hrs). Under the similar conditions, an interesting butterfly cluster [PPh4]2[SeMn2Fe2(CO)12] is obtained by the use of 2M KOH within 25hrs. As the reaction proceeds longer, the butterfly cluster can transform to the octahedral complex and the unknown complex (A). [PPN]2[SeOMn3(CO)9] can be obtained from the mixture of Mo(CO)6, Mn2(CO)10, and SeO2 in a molar ratio of 2：1：3. The novel trigonal bipyramid cluster consists of an equilateral triangle of manganese atoms with the triply bridging oxygen and the selenium atom each positioned above and below the trimanganese plane. It seems that Mo(CO)6 may not participate directly in the reaction but possibly plays the catalytic role by facilitating the oxygen atom to bridge above the Mn3 plane. In this study, all the new compounds are not in agreement with the conventional electron couting rules. Their EPR spectra are indicative of the existence of the metal－base radicals. The butterfly cluster especially shows the characteristic diradical signals. The SQUID analyses reveal the interesting antiferromagnetic interaction. On the other hand, the 77Se NMR and CV analyses are performed as well to understand their properties.
並列關鍵字
cluster參考文獻
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