| Summary: | 碩士 === 國立臺灣師範大學 === 化學研究所 === 91 === To the mixture of Mn2(CO)10 and Cr(CO)6 in the molar ratio of 2 : 1 in 4 M KOH / MeOH solution was added the excess E powder (E = S, Se) which resulted in the formation of the dumbbell compounds [E10Mn6(CO)18]4-. The variation of the molar ratio of E : Mn : Cr or change of the KOH / MeOH concentration showed that the ratio of E : Mn and the higher concentration of KOH / MeOH solution both play important factors in controlling the production of [E10Mn6(CO)18]4- (E = S, Se). [E10Mn6(CO)18]4- (E = S, Se) are both electron precise species, however, the SQUID analysis shows that [S10Mn6(CO)18]4- has 8 unpaired electrons and [Se10Mn6(CO)18]4- has 4 unpaired electrons at room temperature (300 K).
The reactions of [E10Mn6(CO)18]4- (E = S, Se) with Cr(CO)6 formed the trigonal bipyramidal clusters [E2Mn2Cr(CO)9]2-, conversely, the reactions of [E2Mn2Cr(CO)9]2- with the excess E powder converted to [E10Mn6(CO)18]4-. Further reactions of [E10Mn6(CO)18]4- (E = S, Se) with Mn2(CO)10 generated the trigonal bipyramidal clusters [E2Mn3(CO)9]2-. The metallation reaction of [S10Mn6(CO)18]4- with Fe(CO)5 produced the known cluster [SFe3(CO)9]2- while the reaction in the Se case yielded the trigonal bipyramidal unknown cluster 4. If [S10Mn6(CO)18]4- was treated with Mn(CO)5Br, the oxidized product [S4Mn3(CO)10]- was obtained.
Refluxing Se powder, Cr(CO)6 and Ru3(CO)12 in the molar ratio of 3 : 6 : 1 in 2.57 M KOH / MeOH solution for 24h led to the formation of an octahedral cluster [Se2Ru3Cr(CO)10]2- which is a 4 electron deficient species based on the EAN rule.
The reaction of Te powder, Mn2(CO)10, and Fe(CO)5 in the molar ratio of 2 : 2 : 1 in KOH / MeOH solution formed the square pyramidal cluster [Te2Mn2Fe(CO)9]2-. Further reaction with [Cu(CH3CN)4][BF4] afforded the oxidized product [Te2Mn3Fe(CO)12]- resulted from bond breaking and formation processes.
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