Phcl parameter

When the phase correction has been completed, click the Accept button and a message box appears on the screen. If Yes is selected then the xf2p command is executed and the F2 phase corrected spectrum will be calculated and shown on the screen. If No is selected the new values of the PHCO and PHCl parameters are stored for future use but no phase correction is performed. 

Pseudo-first-order rate constants for carbonylation of [MeIr(CO)2l3]" were obtained from the exponential decay of its high frequency y(CO) band. In PhCl, the reaction rate was found to be independent of CO pressure above a threshold of ca. 3.5 bar. Variable temperature kinetic data (80-122 °C) gave activation parameters AH 152 (+6) kj mol and AS 82 (+17) J mol K The acceleration on addition of methanol is dramatic (e. g. by an estimated factor of 10 at 33 °C for 1% MeOH) and the activation parameters (AH 33 ( 2) kJ mol" and AS -197 (+8) J mol" K at 25% MeOH) are very different. Added iodide salts cause substantial inhibition and the results are interpreted in terms of the mechanism shown in Scheme 3.6 where the alcohol aids dissociation of iodide from [MeIr(CO)2l3] . This enables coordination of CO to give the tricarbonyl, [MeIr(CO)3l2] which undergoes more facile methyl migration (see below). The behavior of the model reaction closely resembles the kinetics of the catalytic carbonylation system. Similar promotion by methanol has also been observed by HP IR for carbonylation of [MeIr(CO)2Cl3] [99]. In the same study it was reported that [MeIr(CO)2Cl3]" reductively eliminates MeCl ca. 30 times slower than elimination of Mel from [MeIr(CO)2l3] (at 93-132 °C in PhCl). 

The phase correction parameters PHCO and PHCl are always based on the initial spectrum obtained directly after a Fourier transformation operation. Phasing is performed with respect to a reference point which is marked on the spectrum by the spectrum cursor. When the Phase mode is first entered, the program automatically places the spectrum cursor on the tallest point in the spectrum, but you are free to move this spectrum cursor anywhere in the spectrum using the Maximum Cursor or the Perpendicular Cursor option. 

The kinetics of the reactions of six amines with phenacyl bromide in acetonitrile have been studied conductimetrically at several temperatures and activation parameters were calculated.129 The relative reactivities of the amines were explained in terms of inductive and steric effects. Relative reactivities have been determined conductimetrically for the 2-propanolysis of a series of chlorides and they he in the order PhSCl > PhCOCl > PhS02Cl > PhCH2Cl PhCl, with rate coefficient ratios 9.5 x 104 1 7.14 x 10 2 4.7 x 10-3 10 26.130 (The value for chlorobenzene was estimated.)... 

Depending on the detection mode the appropriate phase mode has to be chosen. The possible options are no, pk, me and ps for no phasing, phase correction using phase constants PHCO and PHCl, magnitude and power spectrum calculation respectively. For further information on these parameters see section 3.2.S.3. 

Time-resolved IR spectroscopy was used to identify cis and trans isomers [W(C0)4L(S)J, L = PPh3, P(0-i-Pr)3, or P(OEt)3 and S = heptane. These isomers were prepared by photolysis of [W(CO)5L] and cw-[W(CO)4L(pip)]. In heptane the cis isomer is shorter lived than the trans isomer there is no evidence for interconversion of the two. The two isomers react with CO with different rates, and the rate increases with the size of L. The term Token Ligand is coined to indicate that there is a specific interaction between a solvent molecule and what would otherwise be a vacant coordination site. Reactions of ds-[W(CO)4L(pip)] with L, L and V = phosphine or phosphite, proceed by reversible pip dissociation, forming square-pyramidal [W(CO)4L] in which L is equatorially coordinated. The general reaction sequence is given in Scheme 6. Dissociative loss of chlorobenzene from ci5-[W(C0)4 P(0-/-Pr)3 (PhCl)] displays activation parameters of A/Zj = 13.0 kcal mol and ASf = -f 5.6 cal K" mol". Rate constants for thermal reactions of ci5-[W(CO)4(L)(PhCl)] with P(0-f-Pr)3, given in Table 10.5, are predominantly... 

A study of the iodination kinetics of dipentene with h in polar and non-polar solvents (EtOH, 1,4-dioxane, CCI4, and PhCl) has revealed that the iodination rate increases with increase in the solvent dielectric constant. The reaction follows a first-, third-, third-, and fourth-order dependence on [I2] in these solvents, respectively. The effect of mixed solvents on iodination rate has also been studied and Arrhenius parameters were calculated. ... 

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