Homo- (Ru) and Heterometallic (Ru─Cu/Cr─Mn) Carbonyl Chalcogenide Clusters: Synthesis, Reactivity, Electrochemistry, UV/Vis Absorption, and Computational Studies

• Main Authors: Chu Yen-Yi, 朱晏頤
• Other Authors: Shieh Minghuey
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/85688205392409549010

博士 === 國立臺灣師範大學 === 化學系 === 103 === 1. E/Ru/CO (E = Se, Te) System The reaction of K2EO3 (E = Se, Te) with Ru3(CO)12 in KOH/MeOH solutions formed tetrahedral ruthenium chalcogenide clusters [HERu3(CO)9]─. When K2EO3 was treated with Ru3(CO)12 in various ratios in superheated MeOH solutions, a family of octahedral clusters [ERu5(CO)14]2─ and [HSe2Ru4(CO)10]─ as well as novel polynuclear clusters [Te4Ru8(CO)19]2─ and [(H)2Se4Ru6(CO)12]2─ were obtained. Additionally, if the reactions were carried out in refluxing MeOH/MeCN solutions, the unstable tetraruthenium chalcogenide clusters [E2Ru4(CO)10]2─ (E = Se, Te) were formed. The hydrido ERu3-clusters [HERu3(CO)9]─ (E = Se, Te) were found to undergo cluster-expansion reactions to form ERu5-clusters [ERu5(CO)14]2─ upon the addition of Ru3(CO)12 in MeCN, whereas clusters [HERu3(CO)9]─ transformed into E2Ru4-clusters [E2Ru4(CO)10]2─ through coupling reactions by the treatment with KOH in MeOH. If clusters [E2Ru4(CO)10]2─ were further treated with K2EO3 (E = Se, Te), the oxidative condensation or dimerization reaction occurred to give clusters [(H)2Se4Ru6(CO)12]2─ and [Te4Ru8(CO)19]2─, respectively. On the other hand, clusters [E2Ru4(CO)10]2─ could be protonated to form clusters [HE2Ru4(CO)10]─, while the ERu5-clusters [ERu5(CO)14]2─ were converted into clusters [HERu5(CO)14]─ upon the acidification. Furthermore, the nature and cluster transformation of these E─Ru─CO clusters were also elucidated by DFT calculations. 2. Se/Ru/ROH (R = Me, Et) System The selective insertion of CO and CO2 into the C─O and O─H bonds of alcohols by the Se─Ru─CO hydride clusters [(-H)Ru4(CO)10Se2]─ and [(3-H)Ru5(CO)14Se]─ was demonstrated by a cooperative effect of the protonic hydride, the electron-rich Ru atom, and the electronegative Se atom as well as the symmetry of the clusters. These reactions generated the first examples of Se-containing ruthenium carboxylate and alkylcarbonate clusters [{(-H)Ru4(CO)10Se2}2{Ru2(CO)4(-1:1-OOCR)}]3─ (R = Me, Et) and [{(-H)-Ru4(CO)10Se2}2{Ru2(CO)4(-1:1-OOCOR)}]3─ (R = Me, Et), respectively. These results disclosed herein provide a new avenue for the capture and storage of CO and CO2 and useful synthetic routes to novel RCOO─- and ROCOO─-bridged ruthenium selenide clusters. 3. Se/Ru/CuX (X = Cl, Br, I) System A series of mono-CuX-SeRu5 clusters [SeRu5(CO)14CuX]2─ (X = Cl, Br, I), bis-CuX-SeRu5 clusters [SeRu5(CO)14(CuX)2]2─ (X = Cl, Br), 6-Cu4X2-linked di-SeRu5 clusters [Se2Ru10(CO)28Cu4X2]2─ (X = Cl, Br), and bis-CuX-Se2Ru4 clusters [Se2Ru4(CO)10(CuX)2]2─ (X = Cl, Br, I) were obtained from the reactions of the octahedral cluster [SeRu5(CO)14]2─ with various ratios of CuX (X = Cl, Br, I) under appropriate conditions. In addition, mono-CuX-SeRu5 clusters [SeRu5(CO)14CuX]2─ (X = Cl, Br) were found to undergo cluster expansion to form bis-CuX-SeRu5 clusters [SeRu5(CO)14(CuX)2]2─ upon the addition of 1 equiv of CuX (X = Cl, Br). Cluster [SeRu5(CO)14(CuBr)2]2─ can expand further to form the 6-Cu4Br2-linked di-SeRu5-cluster [Se2Ru10(CO)28Cu4Br2]2─ in THF at 0 oC via the coupling reaction. Moreover, clusters [Se2Ru10(CO)28Cu4X2]2─ (X = Cl, Br) were converted into bis-CuX-Se2Ru4 clusters [Se2Ru4(CO)10(CuX)2]2─ in MeCN at room temperature. The stepwise cluster transformation, electrochemistry, and UV/Vis absorption of these CuX-incorporated Se─Ru clusters were explored in terms of the effect of CuX as well as metal cores, and further elucidated by DFT calculations. Furthermore, the comparisons with the previously reported analogous Te─Ru─CuX carbonyl clusters were also involved. 4. E/Cr/Mn (E = S, Se, Te) System The reactions of E powder (E = S, Se) with a mixture of Cr(CO)6 and Mn2(CO)10 in concentrated solutions of KOH/MeOH produced two new mixed Cr─Mn─carbonyl clusters, [E2CrMn2(CO)9]2─ (E = S, Se). Clusters [S2CrMn2(CO)9]2─ and [Se2CrMn2(CO)9]2─ were isostructural with one another and each displayed a trigonal-bipyramidal structure, with the CrMn2 triangle axially capped by two 3-E atoms. The analogous telluride cluster, [Te2CrMn2(CO)9]2─, was obtained from the ring-closure of Te2Mn2 ring complex [Te2Mn2Cr2(CO)18]2─. Upon bubbling with CO, clusters [E2CrMn2(CO)9]2─ (E = Se, Te) were readily converted into square-pyramidal clusters, [E2CrMn2(CO)10]2─ (E = Se, Te), accompanied with the cleavage of one Cr─Mn bond. According to SQUID analysis, cluster [Te2CrMn2(CO)9]2─ was paramagnetic, with S = 1 at room temperature; however, the Se analogue was spectroscopically proposed to be diamagnetic, as verified by TD-DFT calculations. Cluster [Te2CrMn2(CO)9]2─ could be further carbonylated, with cleavage of the Mn─Mn bond to produce a new arachno-cluster, [Te2CrMn2(CO)11]2─. The formation and structural isomers, as well as electrochemistry and UV/Vis absorption, of these clusters were also elucidated by DFT calculations.