The Brookhaven Reactor Experiment Control Facility - A Distributed Function Computer Network

Dimmler, D. G.; Greenlaw, N.; Kelley, M.; Potter, David W.; Rankowitz, S.; Stubblefield, F. W.

doi:10.1109/tns.1976.4328277

Cited by 19 publications

(8 citation statements)

References 8 publications

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“…Crystal volume 0.48mm 3. Neutron diffraction data collected at 20 (1)K in a Displex ® model CS-202 closed-cycle He refrigerator* on an automated four-circle diffractometer (Dimmler, Greenlaw, Kelley, Potter, Rankowitz & Stubblefield, 1976;McMullan, Andrews, Koetzle, Reidinger, Thomas & Williams, 1976) International Tables for X-ray Crystallography (1968) and 2.39 m2kg -' used for H (Koetzle & McMullan, 1980). Maximum (sin0)/2 = 0.668 A-'; -7 < h < 7, -9 < k < 0, -18 < l < 0; two intensity monitor reflections remeasured every 50 reflections showed no significant trend; 1813 reflections collected, 815 unique, Rin t = 0.092.…”

Section: H2~ Nh2mentioning

confidence: 99%

A neutron diffraction study of 2,6-diaminopyridine at 20 K

Schwalbe¹,

Williams²,

Koetzle³

1987

Acta Crystallogr C

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Section: H2~ Nh2mentioning

confidence: 99%

A neutron diffraction study of 2,6-diaminopyridine at 20 K

Schwalbe¹,

Williams²,

Koetzle³

1987

Acta Crystallogr C

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“…The sample was placed in a closed-cycle helium refrigerator* and mounted on an automated four-circle diffractometer (Dimmler, Greenlaw, Kelley, Potter, Rankowitz & Stubblefield, 1976;McMullan, Andrews, Koetzle, Reidinger, Thomas & Williams, 1976) at the Brookhaven High Flux Beam Reactor. A beryllium (002) crystal monochromator was employed to obtain a neutron beam of wavelength 1.1302 (2) A (based upon KBr, a = 6.600 A at T = 298 K).…”

Section: (A) Neutron Diffractionmentioning

confidence: 99%

The crystal and molecular structure of 1,1'-ferrocenedicarboxylic acid (triclinic modification): neutron and X-ray diffraction studies at 78 K and 298 K

Takusagawa¹,

Koetzle²

1979

Acta Crystallogr Sect B

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“…. Neutron diffraction data were collected at 100 K on an automated four-circle diffractometer (42,43) at the Brookhaven High Flux Beam Reactor using a Ge(2 2 0) monochromated neutron beam of wavelength 1.15882(7) A (based on KBr, ao = 6.6000 A at 298 K). One reflection (2 0 0) was monitored during cooling (298 K to 100 K) to check the condition ofthe crystal.…”

mentioning

confidence: 99%

Determination of the absolute configuration of (+)-neopentyl-1-d alcohol by neutron and x-ray diffraction analysis.

Yuan

Stevens

Bau

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

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The absolute configuration of (+)-neopentyl-1-d alcohol, prepared by the reduction of 2,2-dimethylpropanal-l-d by actively fermenting yeast, has been determined to be S by neutron diffraction. The neutron study was carried out on the phthalate half ester of neopentyl-l-d alcohol, crystallized as its strychnine salt. The absolute configuration ofthe (-)-strychninium cation was first determined by an x-ray anomalous dispersion study of its iodide salt. The chiral skeleton of strychnine then served as a reference from which the absolute configuration of the -O-CHD-C(CH3)3 group of neopentyl phthalate was determined. Difference Fourier maps calculated from the neutron data showed unambiguously that the -0-CHD-C(CH3)3 groups of both independent molecules in the unit cell had the S configuration. This work proves conclusively that the yeast system reduces aldehydes by delivering hydrogen to the re face of the carbonyl group. The enzymatic reduction of an aldehyde to an alcohol is an important example of a stereospecific biological process that has been studied extensively (1). It is a prototype reaction for many biochemically significant transformations involving the coenzyme NADH. In addition, optically active deuterated alcohols of the type R-CHD-OH have been of great importance in the elucidation of the stereochemistry of displacement reactions at primary carbons (1).The stereospecificity of enzymatic acetaldehyde reduction and ethanol oxidation was established (2-4) when it was discovered that reduction of acetaldehyde-1-d with NADH and yeast alcohol dehydrogenase (ADH) gave ethanol-1-d, which, upon enzymatic reoxidation, returned only acetaldehyde-1-d without loss of deuterium (Scheme I): chemistries were identical. Although neopentyl-1-d and benzyl-1-d alcohols have not been produced by reductions using purified NADH and yeast ADH, it is firmly believed that the NADH/yeast ADH system is responsible for those reductions in the actively fermenting yeast system. The structure ofhorse liver ADH, which is closely related to yeast ADH, has been determined to 2.4-A resolution by x-ray diffraction techniques (9)(10)(11)(12)(13)(14). A model of the active site has been proposed in which the oxygen atom of the substrate binds directly to the zinc atom, which fixes the orientation of the substrate with respect to the coenzyme and controls the stereospecificity of the reaction (14). In this mechanism, direct hydrogen transfer from NADH to substrate is believed to take place.For the most part, the absolute configurations of deuterated alcohols (R-CHD-OH) have been determined by comparison ofNMR and polarimetry data with related molecules ofknown stereochemistry (15, 16). For example, the absolute configuration of ethanol-1-d has been deduced by correlation with a pyranose sugar whose configuration at the CHD center was established by NMR (17) and by correlation with 2-butanol-2-d (18) and pentane-2-d (19) of known configuration. In addition, the absolute configuration of glycolic-d acid, determined by neutron diffrac...

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The Brookhaven Reactor Experiment Control Facility - A Distributed Function Computer Network

Cited by 19 publications

References 8 publications

A neutron diffraction study of 2,6-diaminopyridine at 20 K

A neutron diffraction study of 2,6-diaminopyridine at 20 K

The crystal and molecular structure of 1,1'-ferrocenedicarboxylic acid (triclinic modification): neutron and X-ray diffraction studies at 78 K and 298 K

Determination of the absolute configuration of (+)-neopentyl-1-d alcohol by neutron and x-ray diffraction analysis.

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