Synthesis and Structures of Anionic Closo-Rhodacarborane Clusters Which Contain a Formal Rh(I) Vertex.
Abstract
Isomeric rhodacarboranes closo-3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H11,1a; closo-2,2-(Ph3P)2-2-H-2,1,7-RhC2B9H11, 1b; and closo-2,2-(Ph3P)2-2-H-2,1,12-RhC2B9H11, 1c, react with potassium tri-sec-butylborohydride in THF to produce anionic rhodacarboranes ((Ph3P)2-RhC2B9H11) (2a-c, respectively) tetraalkyl-ammonium salts can be isolated in high yields. The potassium 18-crown-6 salt (2a) and the tetramethylammonium salt (2b) were structurally characterized to determine whether polyhedral distortions could be detected in the solid structure. Complex 2a adopts a regular closo structure while 2b adopts a distorted polyhedral structure in which carbon atoms of the C2B3 bonding face are bent back into the cage, away from the metal. The metal vertex conformations of 2a and 2b with respect to the carborane ligand were in strict agreement with Mingos' molecular orbital predictions. Tetraethylammonium salts of 2a-c each reacted with CO(1 atm. 25 degress C) toproduce in high yeilds (Et4N) (Ph3P) (CO)RhC2B9H11 (3a-c, respectively). Similarly (Et4N)2a and K(18-crown-6)2b reacted with ethylene (1 atm, 25 degrees C) to produce the corresponding salts of ((Ph3P) (N2-C2H4)RhC2B9H11) (4a and 4b, respectively). The new complexes reported here are quite reactive because of their anionic, five-coordinate nature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 15, 1983
- Accession Number
- ADA127028
Entities
People
- Carolyn B. Knobler
- John A. Walker
- M. Frederick Hawthorne
Organizations
- University of California, Los Angeles