Metal vapor synthesis explained

In chemistry, metal vapor synthesis (MVS) is a method for preparing metal complexes by combining freshly produced metal atoms or small particles with ligands. In contrast to the high reactivity of such freshly produced metal atoms, bulk metals typically are unreactive toward neutral ligands. The method has been used to prepare compounds that cannot be prepared by traditional synthetic methods, e.g. Ti(η⁶-toluene)₂. The technique relies on a reactor that evaporates the metal, allowing the vapor to impinge on a cold reactor wall that is coated with the organic ligand. The metal evaporates upon being heated resistively or irradiated with an electron beam. The apparatus operates under high vacuum.^[1] In a common implementation, the metal vapor and the organic ligand are co-condensed at liquid nitrogen temperatures.^{[2] [3] [4] [5] [6] [7]}

In several case where compounds are prepared by MVS, related preparations employ conventional routes. Thus, tris(butadiene)molybdenum was first prepared by co-condensation of butadiene and Mo vapor, but yields are higher for the reduction of molybdenum(V) chloride in the presence of the diene.^[8]

References

1. E. Schmidt, K. J. Klabunde, A. Ponce, A. Smetana, D. Heroux "Metal Vapor Synthesis of Transition Metal Compounds" Encyclopedia of Inorganic Chemistry 2006, John Wiley & Sons.
2. Timms P. L. . 1972 . Transition metal vapors in chemical synthesis. The direct preparation of dibenzene chromium as an undergraduate experiment . J. Chem. Educ. . 49 . 11. 782 . 10.1021/ed049p782 . 1972JChEd..49..782T .
3. J. R. Blackborow, D. Young (2012): "Metal Vapour Synthesis in Organometallic Chemistry" Springer Science & Business Media
4. Review Lecture: The Use of Free Atoms of Transition Metals in Chemical Synthesis . 2397624 . Timms . P. L. . Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences . 1984 . 396 . 1810 . 1–19 . 10.1098/rspa.1984.0106 . 1984RSPSA.396....1T .
5. 10.1021/ar50096a001 . Organic chemistry of metal vapors . 1975 . Klabunde . Kenneth J. . Accounts of Chemical Research . 8 . 12 . 393–399 .
6. METAL-ATOM MEDIATED CHEMICAL TRANSFORMATIONS: The reaction of Group 13 metal atoms with arenes . Hadi . Fergani . 1999 . Sudbury, Ontario . Laurentian University.
7. Book: 10.1002/0470862106.ia137 . Metal Vapor Synthesis of Transition Metal Compounds . Encyclopedia of Inorganic Chemistry . 2005 . Schmidt . Eckhardt . Klabunde . Kenneth J. . Ponce . Aldo . Smetana . Alexander . Heroux . David . 978-0-470-86078-6 .
8. Stephan, G. C. . Naether, C. . Peters, G. . Tuczek, F. . Molybdenum 17- and 18-Electron Bis- and Tris(Butadiene) Complexes: Electronic Structures, Spectroscopic Properties, and Oxidative Ligand Substitution Reactions. Inorg. Chem.. 2013. 52. 10. 5931–5942. 10.1021/ic400145f. 23627292.