ENTHALPIES OF FORMATION OF M(ETA-C5H5)2L COMPLEXES (M = MO, W, TI L = C6H4O2, C10H6O2, C14H8O2)

• Type: Article in International Scientific Journal
• Date: 1988

Authors

DASILVA, MAVR (Author) FCUP; DASILVA, MDMCR (Author) FCUP; DIAS, AR (Author) Other

Journal

Title: Journal of Organometallic Chemistry

Vol. 345

Pages: 105-115

ISSN: 0022-328X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 17 Citations

Scopus - 16 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-TDT

DOI: 10.1016/0022-328x(88)80239-0

Abstract (EN): The standard molar enthalpies of formation, at 298.15 K, of five crystalline bent metallocenes, [M(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf>L] (M = Mo, W, Ti) (LH<inf>2</inf> = 1,2-benzenediol, C<inf>6</inf>H<inf>4</inf>-(OH)<inf>2</inf>; 2,3-napthalenediol, C<inf>10</inf>H<inf>6</inf>(OH)<inf>2</inf>; 9,10-phenanthrenediol, C<inf>14</inf>H<inf>8</inf>(OH)<inf>2</inf>), have been derived from enthalpies of hydrolyses in acid solution measured by precision solution-reaction calorimetry. The results were: ¿H<inf>f</inf>° [Mo(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf>(O<inf>26</inf>H<inf>4</inf>),c] = -130.6±2.9, ¿H<inf>f</inf>°[Mo(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf>(O<inf>2</inf>C<inf>10</inf>H<inf>6</inf>),c] = -80.3± 2.2, ¿H<inf>f</inf>° [ Mo(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf>(O<inf>2</inf>C<inf>14</inf>H<inf>8</inf>,c] = -53.25 ± 10.4, ¿H<inf>f</inf>° [ W(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf> (O<inf>2</inf>C<inf>6</inf>H<inf>4</inf>),c] = -112.8 ±2.9, ¿H<inf>f</inf>° [Ti(¿-C<inf>5</inf>H<inf>5</inf>)<inf>2</inf>(O<inf>2</inf>C<inf>14</inf>H<inf>8</inf>),c] = -322.6 ± 12.7 kJ mol-1. The metaloxygen bond strengths were evaluated as mean bond enthalpy terms (E). Comparison with corresponding values in similar comlexes reveals that small steric energy arises from the binding of a catechol type ligand to a metal atom. © 1988.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11