Metalloles are metallacycle derivatives of cyclopentadiene in which the carbon atom at position 5, the saturated carbon, is replaced by a heteroatom.[1] In contrast to its parent compound, the numbering of the metallole starts at the heteroatom. Some of these compounds are described as organometallic compounds, but in the list below quite a number of metalloids are present too. Some metalloles are fluorescent.[2] Polymeric derivatives of pyrrole and thiophene are of interest in molecular electronics. Metalloles, which can also be viewed as structural analogs of pyrrole, include:
Calculated geometry and inversion barrier energy E for some C4H4MH metalloles[3]
^Dubac, Jacques; Laporterie, Andre; Manuel, Georges (1990). "Group 14 Metalloles. 1. Synthesis, Organic Chemistry, and Physicochemical Data". Chemical Reviews. 90: 215–263. doi:10.1021/cr00099a008.
^Tracy, Henry J.; Mullin, Jerome L.; Klooster, Wim T.; Martin, James A.; Haug, Judith; Wallace, Scott; Rudloe, Isaac; Watts, Kimberly (2005). "Enhanced Photoluminescence from Group 14 Metalloles in Aggregated and Solid Solutions". Inorganic Chemistry. 44 (6): 2003–2011. doi:10.1021/ic049034o. PMID15762727.
^Pelzer, Silke; Wichmann, Karin; Wesendrup, Ralf; Schwerdtfeger, Peter (2002). "Trends in Inversion Barriers IV. The Group 15 Analogous of Pyrrole". The Journal of Physical Chemistry A. 106 (26): 6387. Bibcode:2002JPCA..106.6387P. doi:10.1021/jp0203494.
^Atwood, Jerry L.; Hunter, William E.; Alt, Helmut; Rausch, Marvin D. (1976). "The molecular structure of 1,1-bis(.eta.5-cyclopentadienyl)-2,3,4,5-tetraphenyltitanole and its hafnium analogue". Journal of the American Chemical Society. 98 (9): 2454–2459. Bibcode:1976JAChS..98.2454A. doi:10.1021/ja00425a012.
^Dettlaf G, Weiss E (1976). "Kristallstruktur, 1H-NMR- und Massenspektrum von Tricarbonylferracyclopentadien-tricarbonyleisen, C4H4Fe2(CO)6" [Crystal Structure, Proton NMR and Mass Spectrum of Tricarbonylferracyclopentadienetricarbonyliron, C4H4Fe2(CO)6]. J. Organomet. Chem. 108 (2): 213–23. doi:10.1016/S0022-328X(00)82143-9.