C(21)-H(21B) 0.9800 C(21)-H(21C) 0.9800 C(22)-H(22A) 0.9800 C(22)-H(22B) 0.9800 C(22)-H(22C) 0.9800 C(23)-H(23A) 0.9800 C(23)-H(23B) 0.9800 C(23)-H(23C) 0.9800 C(24)-C(29) 1.395(4) C(24)-C(25) 1.415(3) C(25)-C(26) 1.403(3) C(26)-C(27) 1.392(4) DOW RESTRICTED -For internal use only C(26)-C(26)#1 1.448(5) C(27)-C(28) 1.379(4) C(27)-H(27) 0.9500 C(28)-C(29) 1.393(4) C(28)-H(28) 0.9500 C(29)-H(29) 0.9500 C(30)-C(31) 1.489(4) C(30)-H(30A) 0.9900 C(30)-H(30B) 0.9900 C(31)-H(31A) 0.9800 C(31)-H(31B) 0.9800 C(31)-H(31C) 0.9800 C(32)-C(33) 1.500(4) C(32)-H(32A) 0.9900 C(32)-H(32B) 0.9900 C(33)-H(33A) 0.9800 C(33)-H(33B) 0.9800 C(33)-H(33C) 0.9800 C(34)-H(34A) 0.9800 C(34)-H(34B) 0.9800 C(34)-H(34C) 0.9800 Cl(1A)-C(35A) 1.751(7) Cl(2A)-C(35A) 1.780(8) C(35A)-H(35A) 0.9900 C(35A)-H(35B) 0.9900 Cl(1B)-C(35B) 1.768(10) Cl(2B)-C(35B) 1.754(10) C(35B)-H(35C) 0.9900 C(35B)-H(35D) 0.9900

The products derived from the reaction of sterically hindered sulfur-bridged bisphenols with aluminum trialkyls enable the efficient polymerization of ethylene oxide. The activity of the catalyst is largely determined by the structure of the bisphenol ligand and the size of the aluminum alkyl groups. Bonds of sulfur to aluminum are a common feature of the solid-state structures of compounds examined to this point. In solution, precatalysts of the formula (3-t-Bu-5-Me-2-OAlEt2−C6H2)2S are fluxional, and two processes appear to contribute to the equilibration of all ethyl substituents. The addition of a hindered monomer, 1,2-epoxyhexane, causes the initial formation of solvation complexes with the aluminum precatalysts and effects the disproportionation of the initial dialuminum complex of the bisphenol. One of the polymer end groups appears to be easily replaced by a halide atom during acid workup.

A new ion source incorporating an Integral drift tube allows control over the extent of fragrnentatlon of the quasknolecular ions produced in chemical ionlratlon mass spectrometry. Increasing the electric fleid strength in the drift-tube region causes fragmentation slmllar to that observed at higher source temperatures or with more energetic reagent gases. Effectlve /on temperatures in excess of 1000 K are available at the highest drifl fields. Slnce a slngle drlft voltage settlng controls the extent of fragmentatlon, It is possible to obtain both molecular ion spectra and extenslve fragmentation on successlve scans of a single sample.Chemical ionization mass spectrometry (CIMS) has gained very wide acceptance as an analytical tool in the decade since its initial development ( I ) . One of the greatest advantages of CIMS over electron impact ionization is the great reduction or elimination of fragment ions, simplifying the spectrum and usually producing an intense quasi-molecular ion, i.e., either MH+ or (M -l)+. CI conditions under which only quasimolecular ions are present are ideal for quantitation of a compound, and they greatly facilitate the determination of the number of components or the purity of an unknown sample. However, the molecular weight alone is not sufficient to identify a compound; considerable additional information, such as is available from the masses and intensities of fragment ions, is almost always required.The extent of fragmentation of the quasi-molecular ions in CIMS may be increased by increasing the source temperature (Z), or by using a more energetic reagent gas (3). Both of these methods are relatively slow and experimentally inconvenient and would certainly require the introduction of additional samples with conventional instrumentation.Early in the development of CIMS, it was recognized that increasing the electric field inside the ion source increased the relative intensities of fragment ions (4-6). This effect was attributed to unimolecular fragmentation of the MH' ions activated by energetic collisions with neutral reagent gas molecules in the source. This report describes a drift-tube chemical ionization source which uses this effect to provide a variable degree of fragmentation of the quasi-molecular ions in the CI spectrum.A drift tube is a cylindrical chamber in which a uniform longitudinal electric field is maintained by a series of ring shaped electrodes. Ions introduced into one end of the tube by an ion source may be accelerated through a neutral buffer gas by applying a voltage gradient down the tube. The theory of ion motion in drift tubes has been reviewed by several authors (7-11). Briefly, ions entering a drift tube w i l l acquire energy from the electric field. It has been shown that this energy is related to a parameter EIP, where E = electric field strength, and P = neutral gas pressure in the tube. E / P has lPresent address, Union Carbide 770-120, P.O. Box 8361, South Present address, Stanford Research Institute, Menlo Park, Calif. Charleston, W. Va. 25303. ...

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