MM3 parameterization for the BN dative bond

Fisher, Luke; Holme, Thomas A.

doi:10.1002/jcc.1054

Cited by 8 publications

(7 citation statements)

References 38 publications

(9 reference statements)

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“…Advance Light, manufactured by Brown & Williamson Tobacco Corp., is another recently introduced cigarette brand. Advance Lights combines two new technologies, a special three-part Trionic filter and patented tobacco-curing process that claims to deliver reduced levels of TSNAs and other toxins in smoke . The TSNA levels in these and future modified tobacco products require stringent examination to assess these and other product claims.…”

Section: Discussionmentioning

confidence: 99%

Simultaneous Determination of Five Tobacco-Specific Nitrosamines in Mainstream Cigarette Smoke by Isotope Dilution Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry

Ashley

Watson

2003

Anal. Chem.

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Tobacco-specific nitrosamines (TSNAs) have been previously implicated as a source of carcinogenicity in tobacco and cigarette smoke. Accurate quantification of these chemicals is needed to help assess public health risk. We have developed and validated a specific and sensitive method to simultaneously measure five TSNAs in the particulate phase of mainstream tobacco smoke. Cigarette smoke particulate, produced using standardized machine smoking protocols, was collected on a Cambridge filter pad. The particulate matter was extracted using methylene chloride, back extracted into aqueous solution, further purified by solid-phase extraction, and analyzed by liquid chromatography/electrospray ionization tandem mass spectrometry using isotopically labeled analogues as internal standards. Limits of detection for this method ranged from 0.05 to 1.23 ng/mL using an injection volume of 20 microL. A linear calibration range spanning 2.5-2500 ng/mL was adequate to measure TSNA levels in cigarette smoke. The method achieved excellent reproducibility and accuracy. The identity of each TSNA was established by chromatographic retention time, analyte-specific fragmentation patterns, and relative peak area ratios of two product/precursor ion pairs. This new method provides higher sensitivity, specificity, and throughput than earlier methods for TSNA determination.

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Section: Discussionmentioning

confidence: 99%

Simultaneous Determination of Five Tobacco-Specific Nitrosamines in Mainstream Cigarette Smoke by Isotope Dilution Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry

Ashley

Watson

2003

Anal. Chem.

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“…Ammonia borane and trimethylamine borane (structures shown in Figure ) are simple prototypes that have been studied extensively to investigate dative B–N bonding interactions. − Throughout the years, there have been many different attempts to assign the B–N dative bond stretching frequency in these and similar molecules. In 1957, Rice and co-workers experimentally recorded Raman and infrared spectra of liquid trimethylamine borane and assigned the B–N stretching motion to a peak at 1255 cm –1 .…”

Section: Introductionmentioning

confidence: 99%

Vibrational Spectroscopy of N-Methyliminodiacetic Acid (MIDA)-Protected Boronate Ester: Examination of the B–N Dative Bond

et al. 2011

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N-methyliminodiacetic acid (MIDA)-protected boronate esters are a new class of reagents that offer great promise in iterative Suzuki-Miyaura cross-coupling reactions. Compared to earlier reagents, MIDA esters are easily handled and are benchtop stable under air indefinitely. The success of this new species is tied to its unique molecular architecture. Compared to the simpler B-N containing molecules ammonia borane and trimethylamine borane, MIDA esters are much larger, and the sp(3) hybridized boron atom is secured by two five membered rings, making this molecular class stable for spectroscopic study. Here, we present infrared, Raman, and surface enhanced Raman (SERS) spectra of methylboronic acid MIDA ester. Comparisons of the spectroscopic results to those from electronic structure calculations suggest that the B-N stretching mode in this molecule lies in the range 560-650 cm(-1), making it among the lowest energy vibrations observed to date that can be primarily attributed to B-N stretching.

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“…The relationship between the accurate prediction of charge-transfer frustration, ionicity, and covalency and the structural and energetic characterization of the dative bond has been evaluated to provide a more comprehensive understanding of the dative bond. Besides interest in the fundamental chemical physics of dative bonds, , this approach may be used as a predictive strategy for the structural and energetic properties of dative bonds that have important consequences in the fields of storage and release of hydrogen as a fuel, ,, growth of uniform coatings on individual filaments for fiber-reinforced ceramic matrix composites, − and as new oncological, − cardiovascular, and anti-inflammatory drugs. ,,− …”

Section: Introductionmentioning

confidence: 99%

Covalent and Ionic Nature of the Dative Bond and Account of Accurate Ammonia Borane Binding Enthalpies

Plumley

Evanseck

2007

J. Phys. Chem. A

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The inherent difficulty in modeling the energetic character of the B-N dative bond has been investigated utilizing density functional theory and ab initio methods. The underlying influence of basis set size and functions, thermal corrections, and basis set superposition error (BSSE) on the predicted binding enthalpy of ammonia borane (H3B-NH3) and four methyl-substituted ammonia trimethylboranes ((CH3)3B-N(CH3)nH3-n; n = 0-3) has been evaluated and compared with experiment. HF, B3LYP, MPW1K, MP2, QCISD, and QCISD(T) have been utilized with a wide range of Pople and correlation-consistent basis sets, totaling 336 levels of theory. MPW1K, B3LYP, and HF result in less BSSE and converge to binding enthalpies with fewer basis functions than post-SCF techniques; however, the methods fail to model experimental binding enthalpies and trends accurately, producing mean absolute deviations (MADs) of 5.1, 10.8, and 16.3 kcal/mol, respectively. Despite slow convergence, MP2, QCISD, and QCISD(T) using the 6-311++G(3df,2p) basis set reproduce the experimental binding enthalpy trend and result in lower MADs of 2.2, 2.6, and 0.5 kcal/mol, respectively, when corrected for BSSE and a residual convergence error of ca. 1.3-1.6 kcal/mol. Accuracy of the predicted binding enthalpy is linked to correct determination of the bond's dative character given by charge-transfer frustration, QCTF = -(Delta QN + Delta QB). Frustration gauges the incompleteness of charge transfer between the donor and the acceptor. The binding enthalpy across ammonia borane and methylated complexes is correlated to its dative character (R2 = 0.91), where a more dative bond (less charge-transfer frustration) results in a weaker binding enthalpy. However, a balance of electronic and steric factors must be considered to explain trends in experimentally reported binding enthalpies. Dative bond descriptors, such as bond ionicity and covalency are important in the accurate characterization of the dative bond. The B-N dative bond in ammonia borane is 65% ionic, moderately strong (-27.5 +/- 0.5 kcal/mol), and structurally flexible on the donor side to relieve steric congestion.

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MM3 parameterization for the BN dative bond

Cited by 8 publications

References 38 publications

Simultaneous Determination of Five Tobacco-Specific Nitrosamines in Mainstream Cigarette Smoke by Isotope Dilution Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry

Simultaneous Determination of Five Tobacco-Specific Nitrosamines in Mainstream Cigarette Smoke by Isotope Dilution Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry

Vibrational Spectroscopy of N-Methyliminodiacetic Acid (MIDA)-Protected Boronate Ester: Examination of the B–N Dative Bond

Covalent and Ionic Nature of the Dative Bond and Account of Accurate Ammonia Borane Binding Enthalpies

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