Assignment of the lowest-lying THz absorption signatures in biotin and lactose monohydrate by solid-state density functional theory

Allis, Damian G.; Fedor, Anna M.; Korter, Timothy M.; Bjarnason, J. E.; Brown, E. R.

doi:10.1016/j.cplett.2007.04.032

Cited by 103 publications

(78 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For the purpose, the absorption spectra as shown in Figure 4 have to be deconvoluted to each spectrum. Previously, it was reported that the lowest-lying absorption with peak at 17.5 cm −1 observed in L α ·H 2 O powder can be successfully fitted by Lorentzian [21]. In this work, not only the lowest-lying absorption but also the other absorptions below 55 cm…”

Section: Absorption Property Of Lactose Powdersmentioning

confidence: 59%

Terahertz Time-Domain Spectroscopy to Identify and Evaluate Anomer in Lactose

Yamauchi¹,

Hatakeyam²,

Imai³

et al. 2013

AJAC

View full text Add to dashboard Cite

Lactose powder consisting of α-D-lactose monohydrate and anhydrous β-D-lactose was nondestructively and quantitatively evaluated by transmission-type Terahertz time-domain spectroscopy (THz-TDS). An absorption with peak at 39.7 cm −1 (1.19 THz) was assigned to be derived from anhydrous β-D-lactose, in addition to the absorptions due to α-Dlactose monohydrate with peak at 17.1 cm −1 (0.53 THz) and 45.6 cm −1 (1.37 THz). After deconvolution of the spectra using Lorentzian, integrated intensities of the absorptions with peak at 39.7 cm −1 and 45.6 cm −1 were uniquely dependent on the weight composition ratio of the α-and β-lactose powder. As a result, the net molar-ratio of the α-and β-lactose in lactose powder could be precisely evaluated by the integrated intensity ratio. Further, anomer content in lactose powder extracted from lactose solution was evaluated and the refined and unrefined features were shown by the evaluation method.

show abstract

Section: Absorption Property Of Lactose Powdersmentioning

confidence: 59%

Terahertz Time-Domain Spectroscopy to Identify and Evaluate Anomer in Lactose

Yamauchi¹,

Hatakeyam²,

Imai³

et al. 2013

AJAC

View full text Add to dashboard Cite

show abstract

“…With photon energies in the millielectronvolt (meV) range, electromagnetic radiation at THz frequencies interacts strongly with systems that have characteristic lifetimes in the picosecond range and energetic transitions in the meV range. Examples of such systems include bound electrical charges [1], free charge plasmas [2][3][4], strongly confined charge plasma [5], excitons [6][7][8][9], transient molecular dipoles [10], phonons in crystalline solids [11], weakly bonded molecular crystals [12][13][14][15], relaxational dynamics in aqueous liquids [16][17][18], and hydrated biological matter [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Terahertz spectroscopy and imaging – Modern techniques and applications

Jepsen

Cooke

Koch

2010

Laser & Photonics Reviews

1,745

977

View full text Add to dashboard Cite

Over the past three decades a new spectroscopic technique with unique possibilities has emerged. Based on coherent and time-resolved detection of the electric field of ultrashort radiation bursts in the far-infrared, this technique has become known as terahertz time-domain spectroscopy (THz-TDS). In this review article the authors describe the technique in its various implementations for static and time-resolved spectroscopy, and illustrate the performance of the technique with recent examples from solid-state physics and physical chemistry as well as aqueous chemistry. Examples from other fields of research, where THz spectroscopic techniques have proven to be useful research tools, and the potential for industrial applications of THz spectroscopic and imaging techniques are discussed.

show abstract

“…As most of these fragments are localized on the fused ureido/tetrahydrothiophene (U/T) rings at the "head" of the biotin molecule, the presence of multiple local conformational minima along the covalent potential energy surface are made accessible by flexibility in the -C 4 H 8 -"tail" linking the fused ring head to the carboxylic acid (COOH) pendant group. While multiple local minima have been predicted by previous studies, [23][24][25] the two most interesting conformations of note are a cyclic form predicted in the gas phase (where a pair of H bonds are formed between the U/T rings and the COOH) and the fully-extended form found in the solid-state (where the formation of multiple intermolecular H bonds is preferred over intramolecular H-bond formation). 25 Figure 2 shows a sample of the identified local minima predicted to lie within 40 kJ/mol of the global minimum, as well as the least stable structure optimized to a minimum energy geometry.…”

Section: Biotinmentioning

confidence: 78%

“…While multiple local minima have been predicted by previous studies, [23][24][25] the two most interesting conformations of note are a cyclic form predicted in the gas phase (where a pair of H bonds are formed between the U/T rings and the COOH) and the fully-extended form found in the solid-state (where the formation of multiple intermolecular H bonds is preferred over intramolecular H-bond formation). 25 Figure 2 shows a sample of the identified local minima predicted to lie within 40 kJ/mol of the global minimum, as well as the least stable structure optimized to a minimum energy geometry. Among those conformations within 40 kJ/mol of the global minimum, the stabilities of the biotin molecule geometries are found to increase significantly with H-bond formation between the U/T rings and the COOH.…”

Section: Biotinmentioning

confidence: 78%

Analysis of Diamondoid Mechanosynthesis Tooltip Pathologies Generated via a Distributed Computing Approach

Allis¹,

Helfrich²,

Freitas³

et al. 2011

Jnl of Comp & Theo Nano

View full text Add to dashboard Cite

The results of a combined molecular dynamics/quantum chemistry pathology study of previously reported organic (diamondoid) tooltips for diamondoid mechanosynthesis (DMS) are presented. This study, employing the NanoHive@Home (NH@H) distributed computing project, produced 80,000 tooltip geometries used in 200,000 calculations optimized at either the RHF/3-21G or RHF/STO-3G levels of theory based on geometries obtained from high-energy molecular dynamics simulations to produce highly deformed starting geometries. These 200,000 calculations have been catalogued, grouped according to energies and geometries, and analyzed to consider potentially accessible defect structures (pathologies) for tooltip geometries either binding a carbon dimer (C 2 feedstock or not containing the transported dimer feedstock. The transport and deposition of feedstock and the stability of the tooltip between dimer "loading" cycles are important geometries that must be considered as part of a tooltip stability analysis. The NH@H framework is found to be a useful method both for the study of highly deforming covalent geometries and, using lower-temperature MD simulations, for generating and optimizing molecular conformations (demonstrated using biotin, n-heptane, and n-octane in this study). The results of the pathology survey are discussed and general considerations for the exploration of DMS tooltip usability are explored.

show abstract

Assignment of the lowest-lying THz absorption signatures in biotin and lactose monohydrate by solid-state density functional theory

Cited by 103 publications

References 15 publications

Terahertz Time-Domain Spectroscopy to Identify and Evaluate Anomer in Lactose

Terahertz Time-Domain Spectroscopy to Identify and Evaluate Anomer in Lactose

Terahertz spectroscopy and imaging – Modern techniques and applications

Analysis of Diamondoid Mechanosynthesis Tooltip Pathologies Generated via a Distributed Computing Approach

Contact Info

Product

Resources

About