Boron Monoxide Research Articles

Measurement of boron isotopic ratio with non-gated molecular spectroscopy of femtosecond laser-produced plasma

Laser-induced breakdown spectroscopy can be augmented by concurrent spectroscopic measurements of molecules and molecular ions resulting from recombination of laser-ablated plasmas with the ablated sample and surrounding environment. Molecular emissions can exhibit significantly greater isotopic shifts than atomic emissions, making this approach attractive for isotopic characterization of nuclear materials. We describe a measurement of boron isotopic ratios in four boron-containing samples utilizing the emission from boron monoxide radicals formed in the expanding laser-induced ablation plume. Femtosecond laser excitation is used and the emission in the 532–540nm region of interest is studied, where a linear superposition of characteristic spectra for two boron isotopes has been applied for reconstruction of the boron isotopic ratio. It is also demonstrated that the use of non-gated measurements of emission spectra suffices for accurate isotopic characterization using this method. The application of multivariate regression to deconvolve the isotopic ratio from the measured emission spectra is discussed in detail, including the limitations and subtleties of this approach.

A crossed beam and ab initio investigation on the formation of vinyl boron monoxide (C2H3BO; X1A′) via reaction of boron monoxide (11BO; X2Σ+) with ethylene (C2H4; X1Ag)

The reaction dynamics of the boron monoxide radical ((11)BO; X(2)Σ(+)) with ethylene (C(2)H(4); X(1)A(g)) were investigated at a nominal collision energy of 12.2 kJ mol(-1) employing the crossed molecular beam technique and supported by ab initio and statistical (RRKM) calculations. The reaction is governed by indirect scattering dynamics with the boron monoxide radical attacking the carbon-carbon double bond of the ethylene molecule without entrance barrier with the boron atom. This addition leads to a doublet radical intermediate (O(11)BH(2)CCH(2)), which either undergoes unimolecular decomposition through hydrogen atom emission from the C1 atom via a tight transition state located about 13 kJ mol(-1) above the separated products or isomerizes via a hydrogen shift to the O(11)BHCCH(3) radical, which also can lose a hydrogen atom from the C1 atom. Both processes lead eventually to the formation of the vinyl boron monoxide molecule (C(2)H(3)BO; X(1)A'). The overall reaction was determined to be exoergic by about 40 kJ mol(-1). The reaction dynamics are also compared to the isoelectronic ethylene (C(2)H(4); X(1)A(g)) - cyano radical (CN; X(2)Σ(+)) system studied earlier.

An LIF characterization of supersonic BO (X2Σ+) and CN (X2Σ+) radical sources for crossed beam studies

Various ablation sources generating supersonic boron monoxide (BO; X(2)Σ(+)) radical beams utilizing oxygen (O(2)), carbon dioxide (CO(2)), methanol (CH(3)OH), and water (H(2)O) as seeding gases were characterized in a crossed molecular beams setup by mass resolved time-of-flight spectroscopy and spectroscopically via laser induced fluorescence. Intensities of the sources as well as rovibrational energy distributions were analyzed. The molecular oxygen source was found to produce excessive amount of an unwanted BO(2) byproduct. Internal vibrational energy of boron monoxide generated in the water and methanol sources was too high to be considered for the study of dynamics of ground state radicals. The best combination of intensity, purity, and low internal energy was found in the carbon dioxide source to generate boron monoxide. We successfully tested the boron monoxide (BO; X(2)Σ(+)) radical beam source in crossed beams reactions with acetylene (C(2)H(2)) and ethylene (C(2)H(4)). The source was also compared with supersonic beams of the isoelectronic cyano (CN; X(2)Σ(+)) radical.

Laser Ablation Molecular Isotopic Spectrometry: Parameter influence on boron isotope measurements

Laser Ablation Molecular Isotopic Spectrometry (LAMIS) was recently reported for optical isotopic analysis of condensed samples in ambient air and at ambient pressure. LAMIS utilizes molecular emissions which exhibit larger isotopic spectral shits than in atomic transitions. For boron monoxide 10BO and 11BO, the isotopic shifts extend from 114 cm −1 (0.74 nm) to 145–238 cm −1 (5–8 nm) at the B 2Σ + ( v = 0) → X 2Σ + ( v = 2) and A 2Π i ( v = 0) → X 2Σ + ( v = 3) transitions, respectively. These molecular isotopic shifts are over two orders of magnitude larger than the maximum isotopic shift of approximately 0.6 cm −1 in atomic boron. This paper describes how boron isotope abundance can be quantitatively determined using LAMIS and how atomic, ionic, and molecular optical emission develops in a plasma emanating from laser ablation of solid samples with various boron isotopic composition. We demonstrate that requirements for spectral resolution of the measurement system can be significantly relaxed when the isotopic abundance ratio is determined using chemometric analysis of spectra. Sensitivity can be improved by using a second slightly delayed laser pulse arriving into an expanding plume created by the first ablation pulse.

A crossed beam and ab initio investigation of the reaction of boron monoxide (11BO; X2Σ+) with acetylene (C2H2; X1Σ+g)

The reaction dynamics of boron monoxide (BO; X(2)Σ(+)) with acetylene (C(2)H(2); X(1)Σ(g)(+)) were investigated under single collision conditions at a collision energy of 13 kJ mol(-1) employing the crossed molecular beam technique; electronic structure RRKM calculations were conducted to complement the experimental data. The reaction was found to have no entrance barrier and proceeded via indirect scattering dynamics initiated by an addition of the boron monoxide radical with its boron atom to the carbon-carbon triple bond forming the O(11)BHCCH intermediate. The latter decomposed via hydrogen atom emission to form the linear O(11)BCCH product through a tight exit transition state. The experimentally observed sideways scattering suggests that the hydrogen atom leaves perpendicularly to the rotational plane of the decomposing complex and almost parallel to the total angular momentum vector. RRKM calculations indicate that a minor micro channel could involve a hydrogen migration in the initial collision to form an O(11)BCCH(2) intermediate, which in turn can also emit atomic hydrogen. The overall reaction to form O(11)BCCH plus atomic hydrogen from the separated reactants was determined to be exoergic by 62 ± 8 kJ mol(-1). The reaction dynamics were also compared with the isoelectronic reaction of the cyano radical (CN; X(2)Σ(+)) with acetylene (C(2)H(2); X(1)Σ(g)(+)) studied earlier.

Design of three-dimensional solid-state boron oxide networks:Ab initiocalculations using density functional theory

Most binary oxides are classic examples of densely packed systems; a given compound generally adopts only a small number of structures. Here for boron monoxide (BO) in contrast we demonstrate the existence of many low, equienergetic forms, consistent with the limited experimental NMR data. All are dominated by six-membered rings connected in various ways; there is considerable variation in B-O-B angles and torsion angles but not in bond lengths. The volume per formula unit of a less dense nanoporous phase is twice that of other denser forms.

Thermochemical Properties and Electronic Structure of Boron Oxides BnOm (n = 5−10, m = 1−2) and Their Anions

The molecular and electronic structures of a series of small boron monoxide and dioxide clusters B(n)O(m) (n = 5-10, m = 1, 2) plus their anions were predicted. The enthalpies of formation (DeltaH(f)'s), electron affinities (EAs), vertical detachment energies, and energies of different fragmentation processes are predicted using the G3B3 method. The G3B3 results were benchmarked with respect to more accurate CCSD(T)/CBS values for n = 1-4 with average deviations of +/-1.5 kcal/mol for DeltaH(f)'s and +/-0.03 eV for EAs. The results extend previous observations on the growth mechanism for boron oxide clusters: (i) The low spin electronic state is consistently favored. (ii) The most stable structure of a neutral boron monoxide B(n)O is obtained either by condensing O on a BB edge of a B(n) cycle, or by binding one BO group to a B(n-1) ring. The balance between both factors is dependent on the inherent stability of the boron cycles. (iii) A boron dioxide is formed by incorporating the second O atom into the corresponding monoxide to form BO bonds. (iv) A B(n)O(m)(-) anion is constructed with BO groups bound to the B(n-1) or B(n-2) rings (yielding the B(n-2)(BO)(2)(-) species). This becomes the preferred geometry for the larger boron dioxides, even in the neutral state. The boronyl group mainly behaves as an electron-withdrawing substituent reducing the binding energy and resonance energy of the oxides. (v) The boron oxides conserve some of the properties of the parent boron clusters such as the planarity and multiple aromaticity.

Electronic Transition Moment Variation in the C2Π–X2Σ+ System of Boron Monoxide

The extensive band system belonging to the C2Πr–X2Σ+ transition of boron monoxide (BO) molecule lying in the vacuum ultraviolet region (150–230 nm) has been recorded in emission in a hollow cathode glow. A few new bands involving high v′ levels of C state have been observed. The Franck–Condon factors and r‐centroids were computed for the C–X system. By correlating the measured intensities to theory, the (relative) variation of the C–X electronic transition moment with internuclear separation was examined.

Preparation of aluminum borate nanowires

Single-crystal aluminum borate nanowires (Al18B4O33) with uniform diameter distribution were synthesized by a chemical reaction of alumina with boron monoxide in the presence of a support catalyst. Three comparative experiments were carried out and demonstrated the detailed crystal growth process of the nanowires. We found that two factors, the isolated reaction area with nanometer scale and abundant local reactants at an appropriate reaction temperature, play important roles in determining the diameter, length and yield of the nanowires. The growth mechanism was also prepared.

Infrared laser spectrum of the fundamental band of the boron monoxide free radical

The infrared diode laser absorption spectrum of the fundamental band of the boron monoxide (BO) radical in its ground 2Σ + state has been observed. The source of the radical was the reaction of BCl 3 with O 3 P in the absence of molecular oxygen. 15 lines of 11 BO and three lines of 10 BO have been measured. The 10 BO lines show a small, partially resolved, doublet structure of about 0.01 cm −1 which is not present in the 11 BO species. This is attributed to the complex hyperfine pattern expected for the 10 B ( I=3) nucleus. The band origins are 1861.92465(48) and 1915.30554(16) cm −1 , respectively. Combining the diode laser value of B 1=1.756829(11) cm −1 with the microwave determination of B 0 leads to a value of r e=1.204068(7) Å for 11 BO .

Isolation and structural characterization of novel compounds containing B 4O 2 rings

Two compounds containing planar six-membered B 4O 2 rings have been synthesized and characterized by X-ray crystallography, namely [B 4O 2(OH) 4]·[NH 2Me 2][Cl] and [B 4O 2] (dab 2 = 1,4-Bu t -1,4- diazabutadiene), the former compound providing a model for one possible structure of boron monoxide. {BO} x .

Temperature dependence of the kinetics of the reaction boron monoxide + oxygen

Temperature dependence of the kinetics of the reaction boron monoxide + oxygen

Boron cluster ion oxidation: Reactions with CO2, dissociation of boron cluster oxide (BnO+) ions, and sequential oxidation

Cross sections for oxidation reactions of boron cluster ions (B+1–14) with CO2 are reported as a function of collision energy. The results give insight into the oxidation mechanism and are a sensitive probe of the B+n–O bond energy. In addition, collision-induced dissociation (CID) was used to measure the stabilities of boron monoxide cluster ions (BnO+) and energetic and structural information is obtained that indicates that at least, in some cases, oxidation causes structural rearrangement of the clusters. Sequential oxidation of boron cluster ions by CO2 was also studied and the results give further insight into the reaction mechanism and energetics.

Microwave spectrum of the boron monoxide radical, BO

The microwave spectrum of the boron monoxide radical in the ground electronic state X 2Σ+ has been observed by using a glow discharge cell spectrometer. The boron monoxide radical was generated in an absorption cell by a glow discharge in a gaseous mixture of boron trichloride, nitric oxide, and nitrogen. The observed transitions were N=1–0 and 3–2 in 100 and 300 GHz regions, respectively. The latter transition was observed by using a frequency multiplier working in the 300 GHz region as a microwave source. The spectra of two isotopic species 11BO and 10BO were analyzed to yield molecular parameters including the rotational constants, centrifugal distortion constants, spin-rotation interaction constants, magnetic hyperfine interaction constants, and nuclear quadrupole interaction constants. The spin density of the unpaired σ electron was calculated from the magnetic hyperfine coupling constants and was found to be in good accordance with the result of ab initio calculations.

Rotational Analysis of the A2Π → X2Σ + visible band system of boron monoxide, BO

Seventeen bands of the A 2Π → X 2Σ + system of 11BO with v′ ≤ 8 and v″ ≤ 5, and 13 bands of the same system of 10BO with v′ ≤ 6 and v″ ≤ 4 have been photographed at high resolution and rotationally analyzed. No local perturbations, except for the already known perturbation of A 2Π, v = 4 with X 2Σ +, v = 17 in 11BO have been found for either isotope. The constants obtained from least-squares fits of the line positions of individual bands have been merged for each isotope to obtain single-valued estimates. RKR turning points for the two electronic states are reported.

Comment on the boron(2P) + water .fwdarw. boron monoxide (BO)(X2.SIGMA.,A2.PI.) + molecular hydrogen(X1.SIGMA.g) reaction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComment on the boron(2P) + water .fwdarw. boron monoxide (BO)(X2.SIGMA.,A2.PI.) + molecular hydrogen(X1.SIGMA.g) reactionShogo Sakai and K. D. JordanCite this: J. Phys. Chem. 1983, 87, 13, 2293–2295Publication Date (Print):June 1, 1983Publication History Published online1 May 2002Published inissue 1 June 1983https://doi.org/10.1021/j100236a011RIGHTS & PERMISSIONSArticle Views34Altmetric-Citations18LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (399 KB) Get e-Alerts

The hydrogenation of boron monoxide to diborane and the reactions of boron and boron carbide with titanium and zirconium dioxides

Hydrogenation of boron monoxide or of systems producing it in situ, e.g. a mixture of boric oxide and carbon, above 1000° and at atmospheric pressure, yields diborane (or borine carbonyl) probably via the intermediate formation of boroxine. The reactions of boron and boron carbide with titanium and zirconium dioxides above 1100° in vacuo lead to the formation of the metal diborides and the volatile boron monoxide.

1225. The reduction of boric oxide to boron monoxide

1225. The reduction of boric oxide to boron monoxide

The Preparation of Boron Monoxide and its Conversion to Diboron Tetrachloride1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Preparation of Boron Monoxide and its Conversion to Diboron Tetrachloride1A. L. McCloskey, R. J. Brotherton, and J. L. BooneCite this: J. Am. Chem. Soc. 1961, 83, 23, 4750–4754Publication Date (Print):December 1, 1961Publication History Published online1 May 2002Published inissue 1 December 1961https://doi.org/10.1021/ja01484a015RIGHTS & PERMISSIONSArticle Views626Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (558 KB) Get e-Alerts Get e-Alerts

A new band system of boron monoxide

A new band system of boron monoxide