Octahedral metal carbonyls. 63. Chelate ring displacement of DTHp from cis-(DTHp)W(CO)/sub 4/ by Lewis Bases (DTHp = 2,2,6,6-tetramethyl-3,5-dithiaheptane, Lewis Base = L (phosphine, phosphite))

Journal Article · Wed Sep 21 04:00:00 EDT 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00292a012· OSTI ID:6181236

Dobson, G R; Cortes, J E

Reactions of cis-(DTHp)W(CO)/sub 4/, in which DTHp forms a four-membered chelate ring, with L (DTHp = 2,2,6,6-tetramethyl-3,5-dithiaheptane; L = P(OMe)/sub 3/, P(O-i-Pr)/sub 3/, P(OCH/sub 2/)/sub 3/CCH/sub 3/, P(n-Bu)/sub 3/) in chlorobenzene (CB) proceed via displacement of DTHp according to cis-(DTHp)W(CO)/sub 4/ + 2L ..-->.. cis- and trans-(L)/sub 2/W(CO)/sub 4/ + DTHp. Kinetics data in CB indicate the reaction to be biphasic, with cis-(L)(/eta//sup 1/-DTHp)W(CO)/sub 4/ present as a predominant species during the reaction's course; this intermediate has been characterized for L = P(COH/sub 2/)/sub 3/ CCH/sub 3/. Evidence here suggests that significant L-W bond making takes place in the transition states leading to chelate ring opening and closing. The cis-(L)(/eta//sup 1/-DTHp)W(CO)/sub 4/ products produced via the first phase of the biphasic thermal process undergo unimolecular W-S bond fission. Rate constants for this process vary significantly and are largely influenced by the steric properties of coordinated L, increasing in the order of larger Tolan cone angles. This W-S bond dissociation is followed by solvation to afford cis-((CB)(L)W(CO)/sub 4/) intermediates, previously characterized, which then react via rapid reversible desolvation and attack at the five-coordinate, square-pyramidal ((L)W(CO)/sub 4/) intermediates by L, to afford cis-(L)/sub 2/W(CO)/sub 4/. Subsequent nondissociative isomerization of this species forms the equilibrium mixture of cis- and trans-(L)/sub 2/W(CO)/sub 4/ products ultimately obtained. These several steps involved in the overall chelate displacement process are discussed in detail. 25 references, 4 figures, 2 tables.

• Research Organization: Univ. of North Texas, Denton (USA)
• OSTI ID: 6181236
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:19; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
ALKANES
CARBON 13
CARBON ISOTOPES
CARBONYLS
CHEMICAL REACTIONS
COMPLEXES
DATA
DEUTERIUM
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPE EFFECTS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
SPECTRA
STABLE ISOTOPES
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES