Fluorobenzene-water complexes

The cyciomaitodextrins (a-CD, -CD, and y-CD) can be selectively obtained from a fermentation culture or an enzyme digest of cyclomaltodextrin glucanotransferase reaction with solubilized starch. The majority of the cyclomaltohexaose (a-CD) can be separated from cycloma-Itoheptaose (/3-CD) and y-CD by their selective precipitation with p-cymene from the culture supernatant or from an enzyme digest [168]. The a-CD can then be precipitated from the supernatant with cyclohexene, which is extracted with acetone to remove the cyclohexene and the a-CD can be crystallized from water or a propanol-1/water solution [169]. The p-cymene precipitates of /3-CD and y-CD are put into a water solution and /3-CD selectively precipitated from y-CD with fluorobenzene. The y-CD is then precipitated with anthracene saturated in diethyl ether. After the removal of the fluorobenzene from /3-CD with acetone or ethanol extraction, /3-CD can be crystallized from water, and after the removal of anthracene with acetone or ethanol extraction from y-CD, it can also be crystallized from water [170,171]. The selective precipitations of the cyciomaitodextrins with various organic molecules is based on the selective formation of complexes of the organic molecules with the specific sizes of the cyciomaitodextrins and the relatively hydrophobic interior cavities of the cyciomaitodextrins [166,167,168]. 

Arenediazonium ion reactions often are complex.61 Benzenediazonium fluoro-borate in 2,2,2-trifluoro ethanol (TFE), for example, decomposes by first-order kinetics to give a mixture consisting largely of the ether (62%) formed by solvolysis and fluorobenzene (34%) resulting from reaction with fluoroborate ion. Addition of pyridine changes the kinetic order and gives rise to additional products.62 The same diazonium ion solvolyzes faster in TFE than in water. Because water is a better nucleophile than TFE, it is likely that a nucleophile is not involved in the rate limiting step of the reaction.63 ... 

Figure 7. The optimal structures (MP2/aug-cc-pVDZ) of the 7i-(H20)m clusters (D p-difluorobenzene, F fluorobenzene, B benzene, T toluene, W H2O). Note the ct to 7t transition observed in the water trimer complexes of fluorobenzene and p-difluorobenzene.

Ru (Tp)(Cl)(PPh3)(MeCN)] serves as a starting material for the synthesis of new ruthenium complexes. Water was also involved in the reactions of this Ru—Tp complex with phenylacetylene and l-ethynyl-4-fluorobenzene that yields the alkenyl ketone compound [Ru(Tp)(PPh3)(C(CH2Ph)= CHC(O)Ph)] and the acyl complex [Ru(Tp)(PPh3)(C(0)CH2(C6H5)F)]. ... 

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