Structure and Solution Dynamics of [(Ph3P)2Pd(Ph)(FHF)]

Autor:	D. Christopher Roe, William J. Marshall, and Paul D. Soper, Vladimir V. Grushin, Fredric Davidson
Rok vydání:	2000
Předmět:	Inorganic Chemistry Bifluoride chemistry.chemical_compound Crystallography chemistry Intramolecular force Organic Chemistry Fluorine-19 NMR 31p nmr spectroscopy Magnetization transfer Physical and Theoretical Chemistry Solution structure Dissociation (chemistry)
Zdroj:	Organometallics. 19:4575-4582
ISSN:	1520-6041 0276-7333
DOI:	10.1021/om000637r
Popis:	The bifluoride complex trans-[(Ph3P)2Pd(Ph)(FHF)] (1) was studied by single-crystal X-ray diffraction, IR, and variable-temperature 1H, 19F, and 31P NMR spectroscopy. Like other transition-metal bifluorides, 1 exhibits fluxional behavior (NMR) in solution at room temperature. When exchange processes are frozen (−60 °C), the solution structure of 1 is consistent with the solid-state X-ray data. Although all structural and spectroscopic data point to MF···HF rather than M···FHF character for 1, 19F NMR magnetization transfer experiments demonstrated a minor contribution of HF dissociation to the exchange. The main process that governs F/F exchange in 1 is intramolecular (ΔH⧧ = 33.7 ± 2.1 kJ mol-1; ΔS⧧ = −56.1 ± 9.6 J mol-1 K-1), likely occurring via pentacoordinate [(Ph3P)2Pd(Ph)(η2-FHF)], in which both fluorines are coordinated to Pd. DFT calculations for two model Pd bifluoride complexes [(R3P)2Pd(Me)(FHF)] (R = H, Me) indicated virtually unrestricted rotation around the Pd−FHF bond.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7e55e8f4dab7841e9c0a57fcfa370a98 https://doi.org/10.1021/om000637r Zobrazit plný text záznamu