Garry Grubbs | Missouri University of Science and Technology (original) (raw)

Papers by Garry Grubbs

The Journal of Chemical Physics, 2017

Review of Scientific Instruments, 2007

The ablation of metal surfaces in the presence of a precursor gas produces reaction products whic... more The ablation of metal surfaces in the presence of a precursor gas produces reaction products which are often difficult to predict and highly dependent on ablation conditions. This article describes the successful development and implementation of a laser ablation source-equipped Fourier transform microwave spectrometer capable of observing 4 GHz regions of spectra in a single data acquisition event. The dramatically increased speed with which regions may be searched, when compared to other high resolution microwave techniques, allows the source conditions to be the prime variable in laser ablation microwave spectroscopic studies. A second feature of the technique is that observed spectral features have correct relative intensities. This is advantageous when assigning observed spectra. The study of two metal chlorides, AgCl and AuCl, illustrate the instrument's benefits.

Journal of Molecular Spectroscopy, 2011

Drinfel'd used associators to construct families of universal representations of braid groups. We... more Drinfel'd used associators to construct families of universal representations of braid groups. We consider semi-associators (i.e., we drop the pentagonal axiom and impose a normalization in degree one). We show that the process may be reversed, to obtain semi-associators from universal representations of 3-braids. We view braid groups as subgroups of braid-permutation groups. We construct a family of universal representations of braid-permutation groups, without using associators. All representations in the family are faithful, defined over Q by simple explicit formulae. We show that they give universal Vassiliev-type invariants for braid-permutation groups.

Journal of Molecular Spectroscopy, 2011

New molecular structural data is presented for a cyanide terminated oligomer of polytetrafluoroet... more New molecular structural data is presented for a cyanide terminated oligomer of polytetrafluoroethene. The target molecule, CF 3-(CF 2) 6-CN, has been seeded within a pulsed supersonic expansion of argon. The result of this action is to cool the species to rotational temperatures below 4 K. Within this state, the pure rotational spectrum of the oligomer has been recorded using two types of Fourier transform microwave spectroscopy. A total of 111 transitions have been identified involving rotational J levels between 6 and 40. Only a-and b-type transitions were observed. The spectrum has been analyzed using a Hamiltonian containing all three rotational constants and one centrifugal distortion constant, D J. The experimental spectroscopic constants have been used to develop an effective molecular structure by scaling the quantum chemical calculated structure. The data shows that the seven carbon perfluorinated chain for the isolated oligomer twists %104°. This compares well to the C 7 F 13-twist of %97°anticipated from the X-ray structure of phase II polytetrafluoroethene.

The Journal of Chemical Physics, 2012

An interpolating moving least squares method is used to fit ab initio points to obtain an intermo... more An interpolating moving least squares method is used to fit ab initio points to obtain an intermolecular potential energy surface (PES) for (CO 2) 2. The surface is used in conjunction with the symmetry-adapted Lanczos algorithm to compute rovibrational transition frequencies. The PES has four equivalent minima separated by barriers high enough that tunneling splittings are very small. The lowest energy pathway connecting the minima is a disrotatory channel. The calculations enable us to assign a combination band observed by Dehghany et al. [ Mol. Phys. 108, 2195(2010) ].

Molecular Physics, 2018

The microwave spectrum of 3-bromo-1,1,1,2,2-pentafluoropropane has been observed using CP-FTMW sp... more The microwave spectrum of 3-bromo-1,1,1,2,2-pentafluoropropane has been observed using CP-FTMW spectroscopy. Potential energy scans have been performed and confirm the existence of two conformers-trans and gauche-for which further structural optimisations and electric field gradient calculations have been performed in order to get highly accurate nuclear quadrupole coupling constants for assignment purposes. The combination of multiple conformers and large nuclear quadrupole coupling constants produce a very dense spectrum at an estimated 1 transition/MHz, near the continuum limit. This spectral density makes it necessary to have very sophisticated computational approaches in order to get geometric and electronic structures that are very close to experimental observation. Analysis of the spectrum allowed for the assignment of the trans conformer, but the gauche proved to be prohibitive, although it is believed to be present in the current spectrum. Full analysis of the rotational spectroscopic parameters of two isotopologues-the 79 Br and 81 Br-have been observed and are reported. Geometric analysis of the experimentally observed conformer is also reported using Kraitchman coordinate and second moments arguments. Further analysis of the spectrum reveals the occurrence of dipole-forbidden, nuclear quadrupole allowed transitions with one forbidden transition possessing the first known x-type forbidden transition linkage pathway.

Symmetry

This manuscript details the construction and demonstration of the first known microwave three-wav... more This manuscript details the construction and demonstration of the first known microwave three-wave mixing (M3WM) experiment utilizing multiple arbitrary waveform generators (AWGs) completely operable in the 6–18 GHz frequency range for use in chirality determination and quantification. Many M3WM techniques, which involve two orthogonal, subsequent Rabi π/2 and π microwave pulses, suffer from flexibility in pulse types and timings as well as frequency due to most instruments only using one, one-channel AWG and the M3WM probability decreasing with an increasing quantum number, J. In this work, we presented an M3WM instrument that allows that flexibility by introducing multiple, synchronized AWGs and adheres to the high probability transition loop pathways in carvone. The functionality and reliability of the instrument were demonstrated using a series of experiments and mixtures of the R and S enantiomers and determined to be of similar accuracy to other reported M3WM setups with the a...

Parent file fits in SPFIT/SPCAT

Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#30507... more Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#305070, Denton, Tx 76203-5017, U.S.A

Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Dent... more Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203-5070

Author Institution: Chemistry-Physics Department (Retired), Kean University; Union, New Jersey, U... more Author Institution: Chemistry-Physics Department (Retired), Kean University; Union, New Jersey, USA 07083; Departments of Chemistry and Physics, University of Connecticut,Storrs, Connecticut, 06269-3060, USA.; Department of Chemistry, Wesleyan University, Hall-Atwater Laboratories, 52 Lawn Ave, Middletown, Connecticut, 06459-0180, USA.; Institute of Physics, Polish Academy of Sciences, Al. Lotnikov 32146, 02-668 Warszawa, Poland.; School of Natural and Social Sciences, Purchase College SUNY, 735 Anderson Hill Road, Purchase, NY 10577, USA

All SPFIT/SPCAT input files and rm1L files used in STRFIT as reported in the manuscript.

Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, # ... more Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, # 305070 Denton, TX 76203-5017, USA; Department of Chemistry, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, MO 64110

Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Dent... more Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203-5070

BRITTANY E. LONG, Chemistry Department, Trinity University, San Antonio, TX, USA; JUAN BETANCUR, ... more BRITTANY E. LONG, Chemistry Department, Trinity University, San Antonio, TX, USA; JUAN BETANCUR, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA; YOON JEONG CHOI, Department of Chemistry, Wesleyan University, Middletown, CT, USA; S. A. COOKE, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA; G. S. GRUBBS II, Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, USA; JONATHAN OGULNICK, TARA HOLMES, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA.

Author Institution: Department of Chemistry, The University of North Texas, P. O. Box 305070, Den... more Author Institution: Department of Chemistry, The University of North Texas, P. O. Box 305070, Denton, Texas, 76203, U.S.A

Author Institution: Department of Chemistry, Eastern Illinois University, 600 Lincoln Ave., Charl... more Author Institution: Department of Chemistry, Eastern Illinois University, 600 Lincoln Ave., Charleston, IL 61920; Department of Chemistry, University of North Texas, PO Box 305070, Denton, TX 76203; Department of Chemistry, University of Virginia, McCormick Rd., PO Box 400319, Charlottesville, VA 22904

Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, #3... more Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, U.S.A.; Department of Chemistry, Wesleyan University, Hall-Atwater Laboratories, 52 Lawn Ave., Middletown, CT 06459-0180, U.S.A

Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#30507... more Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#305070, Denton, Tx 76203-5017, U.S.A

Journal of Molecular Structure

The Journal of Chemical Physics, 2017

Review of Scientific Instruments, 2007

The ablation of metal surfaces in the presence of a precursor gas produces reaction products whic... more The ablation of metal surfaces in the presence of a precursor gas produces reaction products which are often difficult to predict and highly dependent on ablation conditions. This article describes the successful development and implementation of a laser ablation source-equipped Fourier transform microwave spectrometer capable of observing 4 GHz regions of spectra in a single data acquisition event. The dramatically increased speed with which regions may be searched, when compared to other high resolution microwave techniques, allows the source conditions to be the prime variable in laser ablation microwave spectroscopic studies. A second feature of the technique is that observed spectral features have correct relative intensities. This is advantageous when assigning observed spectra. The study of two metal chlorides, AgCl and AuCl, illustrate the instrument's benefits.

Journal of Molecular Spectroscopy, 2011

Drinfel'd used associators to construct families of universal representations of braid groups. We... more Drinfel'd used associators to construct families of universal representations of braid groups. We consider semi-associators (i.e., we drop the pentagonal axiom and impose a normalization in degree one). We show that the process may be reversed, to obtain semi-associators from universal representations of 3-braids. We view braid groups as subgroups of braid-permutation groups. We construct a family of universal representations of braid-permutation groups, without using associators. All representations in the family are faithful, defined over Q by simple explicit formulae. We show that they give universal Vassiliev-type invariants for braid-permutation groups.

Journal of Molecular Spectroscopy, 2011

New molecular structural data is presented for a cyanide terminated oligomer of polytetrafluoroet... more New molecular structural data is presented for a cyanide terminated oligomer of polytetrafluoroethene. The target molecule, CF 3-(CF 2) 6-CN, has been seeded within a pulsed supersonic expansion of argon. The result of this action is to cool the species to rotational temperatures below 4 K. Within this state, the pure rotational spectrum of the oligomer has been recorded using two types of Fourier transform microwave spectroscopy. A total of 111 transitions have been identified involving rotational J levels between 6 and 40. Only a-and b-type transitions were observed. The spectrum has been analyzed using a Hamiltonian containing all three rotational constants and one centrifugal distortion constant, D J. The experimental spectroscopic constants have been used to develop an effective molecular structure by scaling the quantum chemical calculated structure. The data shows that the seven carbon perfluorinated chain for the isolated oligomer twists %104°. This compares well to the C 7 F 13-twist of %97°anticipated from the X-ray structure of phase II polytetrafluoroethene.

The Journal of Chemical Physics, 2012

An interpolating moving least squares method is used to fit ab initio points to obtain an intermo... more An interpolating moving least squares method is used to fit ab initio points to obtain an intermolecular potential energy surface (PES) for (CO 2) 2. The surface is used in conjunction with the symmetry-adapted Lanczos algorithm to compute rovibrational transition frequencies. The PES has four equivalent minima separated by barriers high enough that tunneling splittings are very small. The lowest energy pathway connecting the minima is a disrotatory channel. The calculations enable us to assign a combination band observed by Dehghany et al. [ Mol. Phys. 108, 2195(2010) ].

Molecular Physics, 2018

The microwave spectrum of 3-bromo-1,1,1,2,2-pentafluoropropane has been observed using CP-FTMW sp... more The microwave spectrum of 3-bromo-1,1,1,2,2-pentafluoropropane has been observed using CP-FTMW spectroscopy. Potential energy scans have been performed and confirm the existence of two conformers-trans and gauche-for which further structural optimisations and electric field gradient calculations have been performed in order to get highly accurate nuclear quadrupole coupling constants for assignment purposes. The combination of multiple conformers and large nuclear quadrupole coupling constants produce a very dense spectrum at an estimated 1 transition/MHz, near the continuum limit. This spectral density makes it necessary to have very sophisticated computational approaches in order to get geometric and electronic structures that are very close to experimental observation. Analysis of the spectrum allowed for the assignment of the trans conformer, but the gauche proved to be prohibitive, although it is believed to be present in the current spectrum. Full analysis of the rotational spectroscopic parameters of two isotopologues-the 79 Br and 81 Br-have been observed and are reported. Geometric analysis of the experimentally observed conformer is also reported using Kraitchman coordinate and second moments arguments. Further analysis of the spectrum reveals the occurrence of dipole-forbidden, nuclear quadrupole allowed transitions with one forbidden transition possessing the first known x-type forbidden transition linkage pathway.

Symmetry

This manuscript details the construction and demonstration of the first known microwave three-wav... more This manuscript details the construction and demonstration of the first known microwave three-wave mixing (M3WM) experiment utilizing multiple arbitrary waveform generators (AWGs) completely operable in the 6–18 GHz frequency range for use in chirality determination and quantification. Many M3WM techniques, which involve two orthogonal, subsequent Rabi π/2 and π microwave pulses, suffer from flexibility in pulse types and timings as well as frequency due to most instruments only using one, one-channel AWG and the M3WM probability decreasing with an increasing quantum number, J. In this work, we presented an M3WM instrument that allows that flexibility by introducing multiple, synchronized AWGs and adheres to the high probability transition loop pathways in carvone. The functionality and reliability of the instrument were demonstrated using a series of experiments and mixtures of the R and S enantiomers and determined to be of similar accuracy to other reported M3WM setups with the a...

Parent file fits in SPFIT/SPCAT

Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#30507... more Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#305070, Denton, Tx 76203-5017, U.S.A

Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Dent... more Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203-5070

Author Institution: Chemistry-Physics Department (Retired), Kean University; Union, New Jersey, U... more Author Institution: Chemistry-Physics Department (Retired), Kean University; Union, New Jersey, USA 07083; Departments of Chemistry and Physics, University of Connecticut,Storrs, Connecticut, 06269-3060, USA.; Department of Chemistry, Wesleyan University, Hall-Atwater Laboratories, 52 Lawn Ave, Middletown, Connecticut, 06459-0180, USA.; Institute of Physics, Polish Academy of Sciences, Al. Lotnikov 32146, 02-668 Warszawa, Poland.; School of Natural and Social Sciences, Purchase College SUNY, 735 Anderson Hill Road, Purchase, NY 10577, USA

All SPFIT/SPCAT input files and rm1L files used in STRFIT as reported in the manuscript.

Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, # ... more Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, # 305070 Denton, TX 76203-5017, USA; Department of Chemistry, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, MO 64110

Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Dent... more Author Institution: The Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203-5070

BRITTANY E. LONG, Chemistry Department, Trinity University, San Antonio, TX, USA; JUAN BETANCUR, ... more BRITTANY E. LONG, Chemistry Department, Trinity University, San Antonio, TX, USA; JUAN BETANCUR, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA; YOON JEONG CHOI, Department of Chemistry, Wesleyan University, Middletown, CT, USA; S. A. COOKE, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA; G. S. GRUBBS II, Department of Chemistry, Missouri University of Science and Technology, Rolla, MO, USA; JONATHAN OGULNICK, TARA HOLMES, Natural and Social Science, Purchase College SUNY, Purchase, NY, USA.

Author Institution: Department of Chemistry, The University of North Texas, P. O. Box 305070, Den... more Author Institution: Department of Chemistry, The University of North Texas, P. O. Box 305070, Denton, Texas, 76203, U.S.A

Author Institution: Department of Chemistry, Eastern Illinois University, 600 Lincoln Ave., Charl... more Author Institution: Department of Chemistry, Eastern Illinois University, 600 Lincoln Ave., Charleston, IL 61920; Department of Chemistry, University of North Texas, PO Box 305070, Denton, TX 76203; Department of Chemistry, University of Virginia, McCormick Rd., PO Box 400319, Charlottesville, VA 22904

Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, #3... more Author Institution: Department of Chemistry, The University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, U.S.A.; Department of Chemistry, Wesleyan University, Hall-Atwater Laboratories, 52 Lawn Ave., Middletown, CT 06459-0180, U.S.A

Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#30507... more Author Institution: Department of Chemistry, University of North Texas, 1155 Union Circle \#305070, Denton, Tx 76203-5017, U.S.A

Journal of Molecular Structure