September 2006 Meeting
The three hundred and sixty-fifth meeting of the Section will be held on Wednesday, 20 September 2006 at Bloomsburg University in Monty's Dining Hall on the Upper Campus. The guest speaker is Joseph D. Larkin. He will present a talk entitled "A Computational Investigation of the Structure and Protodeboronation of BoroGlycine, H2N-CH2-B(OH)2".
Dinner and Meeting: will begin at at 6:00 p.m.
Lecture: will begin at 7:30 p.m.
Dinner: There are three dinner choices: London broil, salmon, or vegetarian. The cost will be $20.00 per person. Please RSVP to Sharlene Pollock (570-389-5159) or spollock@bloomu.edu by 5:00 p.m. on Wednesday, 13 Sept. 2006.
See directions below.
"A Computational Investigation of the Structure and Protodeboronation of BoroGlycine, H2N-CH2-B(OH)2"
Despite the widespread use of boronic acids in materials science, as pharmaceutical agents, and in the synthesis of biologically active compounds, many aspects of their structure and reactivity are not well understood. The structure of the simple, achiral, a-amino boronic acid BoroGlycine, H2N-CH2-B(OH)2, was investigated using density functional theory (DFT), second-order Møller-Plesset (MP2) perturbation theory, and coupled cluster methodology with single- and double-excitations (CCSD); the effects of an aqueous environment were incorporated into the results by using explicit water molecules and/or self-consistent reaction field (SCRF) calculations with the (IEF) Polarizable Continuum Model (PCM). Neutral reaction mechanisms were investigated for the direct protodeboronation of H2N-CH2-B(OH)2 that yields B(OH)3 and H2N-CH3, as well as for the 1,2-carbon-to-nitrogen shift of the -B(OH)2 moiety that yields the homologous structure methylamine boronic acid, H3C-NH-B(OH)2. The hydrolysis of BoroGlycine:
H2O + H2N-CH2-B(OH)2 → B(OH)3 + H2N-CH3,
and the interconversion:
H2N-CH2-B(OH)2 → H3C-NH-B(OH)2,
were shown to be exothermic, DHo298 = -21.9 and -18.2 kcal/mol respectively at the MP2(FC)/aug-cc-pVDZ level. The activation barrier for the direct protodeboronation of H2N-CH2-B(OH)2, DH‡ = 37.0 kcal/mol, was higher than that for the 1,2-migration of the -B(OH)2 moiety in the presence of a single water molecule, DH‡ = 28.3 kcal/mol. A boron-oxygen double-bonded intermediate was shown to play an important role in the 1,2-rearrangement mechanism.
Joseph D. Larkin earned his undergraduate degree at Philadelphia University. He earned a Ph.D. at the University of Georgia working with Henry F. Schaefer and collaborating with Bernard R. Brooks at the National Institute of Health. His research interest lies in the area of electronic structure and reaction pathway modeling. Joe is currently in his first year of a tenure track position at Bloomsburg University.
Directions:
East of Bloomsburg: Use I-80 west to Exit 236A south.
West of Bloomsburg: Use I-80 east to Exit 236 south.
South of Bloomsburg:
From Central Pennsylvania, take Routes 11 and 15 north to the Town of Bloomsburg. Heading north on Main Street, you'll see Carver Hall directly ahead, and you'll arrive on the western end of the campus
From southeast Pennsylvania, take Northeast Extension of the Pennsylvania Turnpike (I-476) to I-80 west (Pocono Exit) to Exit 236A south.
North of Bloomsburg:
From the Scranton/Wilkes-Barre area, take I-81 south to I-80 west to Exit 236A south.
From the Williamsport area, take I-180 south to I-80 east to Exit 236.
From Exit 236 on I-80, take Route 487 south and follow signs to campus, approximately one mile. You'll arrive on the eastern end of campus. Refer to the BloomU map to locate Monty's on the Upper Campus.
Parking
Generally there is plenty of parking available on the upper campus.
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