Synthesis and Rearrangements of Aminosubstituted Ferra- and Ruthenatricarbaboranes Josef Holub, † Bohumı ´r Gru 1 ner, † Dmitry S. Perekalin, ‡ Denis G. Golovanov, ‡ Konstantin A. Lyssenko, ‡ Pavel V. Petrovskii, ‡ Alexander R. Kudinov,* ,‡ and Bohumil S ˇ tı ´br* ,† Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic (Research Center for New Inorganic Compounds and AdVanced Materials, UniVersity of Pardubice), 250 68, R ˇ ez ˇ, Czech Republic, and A. N. NesmeyanoV Institute of Organoelement Compounds, Russian Academy of Sciences, 28 ul. VaViloVa, 119991 Moscow GSP-1, Russian Federation Received November 18, 2004 A room-temperature reaction between the [7- t BuNH-nido-7,8,9-C 3 B 8 H 10 ] - anion (1a) and [Cp*RuCl] 4 leads to the ruthenatricarbollide [1-Cp*-12- t BuNH-1,2,4,12-RuC 3 B 8 H 10 ](2) (yield 85%). Analogously, the room-temperature photochemical reaction of 1a with [CpFe(C 6 H 6 )]PF 6 gives the previously reported iron complex [1-Cp-12- t BuNH- 1,2,4,12-FeC 3 B 8 H 10 ](3) (yield 82%). Both reactions are associated with extensive polyhedral rearrangement, which occurs under very mild conditions and brings the carbon atoms to positions of maximum separation within the framework. Compounds 2 and 3 were also surprisingly obtained via complexation of the isomeric [8- t BuNH-nido- 7,8,9-C 3 B 8 H 10 ] - (1b) anion. Complex 2 rearranges further to [1-Cp*-10- t BuNH-1,2,4,10-RuC 3 B 8 H 10 ](4) upon refluxing in xylene (145 °C). Density functional theory calculations at the B3LYP/SDD level were used to estimate relative stabilities of these metallacarborane isomers. Compounds 2 and 4, along with the 11-vertex closo compounds [1-Cp*-1,2,3,10-RuC 3 B 7 H 10 ](5) and [1-Cp*-10- t BuNH-1,2,3,10-RuC 3 B 7 H 9 ](6), were also isolated from the reaction between [Cp*RuCl 2 ] 2 and 1a in boiling xylene. The structure of 2 was established by an X-ray diffraction study, and the constitution of all compounds was determined unambiguously by multinuclear NMR spectroscopy, mass spectrometry, and elemental analyses. Introduction It was reported 1 that the reaction between [CpFe(CO) 2 I] and [7,8,9-C 3 B 8 H 11 ] - in refluxing toluene results in the formation of [1-Cp-1,2,4,10-FeC 3 B 8 H 11 ](7) as the main reaction product. In contrast, a similar reaction of the aminosubstituted analogue, [7- t BuNH-7,8,9-C 3 B 8 H 10 ] - (1a), gives the cage-isomeric ferratricarbollide [1-Cp-12- t BuNH- 1,2,4,12-FeC 3 B 8 H 10 ](3) (see path a of Scheme 1). 2 The formation of 3 is associated with an extensive rearrangement that moves the cluster carbons into positions of maximum space separation within the 12-vertex closo-FeC 3 B 8 cage. Complex 3, containing the substituted cage carbon atom in the para position with respect to the Fe center, can be converted into the thermodynamically more stable meta isomer, [1-Cp-10- t BuNH-1,2,4,10-FeC 3 B 8 H 10 ](8) (derivative of the unsubstituted compound 7), via thermal rearrangement at high temperatures (path b of Scheme 1). 3 A general feature of the rearrangement-complexation reactions outlined above is that they must be thermally induced, which applies to most * Authors to whom correspondence should be addressed. E-mail: arkudinov@ineos.ac.ru (A.R.K.); stibr@iic.cas.cz (B.S.). † Academy of Sciences of the Czech Republic. ‡ Russian Academy of Sciences. (1) S ˇ tı ´br, B.; Holub, J.; Teixidor, F.; Vin ˜as, C. Collect. Czech. Chem. Commun. 1995, 60, 2023. (2) Holub, J.; Gru ¨ner B.; Cı ´sar ˇova ´, I.; Fusek, J.; Plza ´k, Z.; Teixidor, F.; Vin ˜as, C.; S ˇ tı ´br, B. Inorg. Chem. 1999, 38, 2775. (3) Gru ¨ner, B.; Lehtonen, A.; Kiveka ¨s, R.; Sillanpa ¨a ¨, R.; Holub, J.; Teixidor, F.; Vin ˜as, C.; S ˇ tı ´br, B. Inorg. Chem. 2000, 39, 2577. Scheme 1. Formation of Isomeric Ferratricarbollides via Rearrangement-Complexation and Thermal Isomerization a a Key: (a) [CpFe(C6H6)]PF6, CH2Cl2, visible light irradiation, room temperature (this work) or CpFe(CO)2I, xylene reflux, see ref 2. (b) Mesitylene, reflux, see ref 3. Inorg. Chem. 2005, 44, 1655-1659 10.1021/ic0483702 CCC: $30.25 © 2005 American Chemical Society Inorganic Chemistry, Vol. 44, No. 6, 2005 1655 Published on Web 02/23/2005