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SODIATED SUGAR STRUCTURES: CRYOGENIC ION VIBRATIONAL SPECTROSCOPY OF Na+(GLUCOSE) ADDUCTS
JONATHAN M. VOSS, STEVEN J. KREGEL, KAITLYN C. FISCHER, & ETIENNE GARAND
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Noncovalent Carbohydrate Interactions
Biomass to chemical feedstocks Dissolution of cellulose by ionic liquids Breakdown of glucose enhanced by inorganic salts Salts alter anomeric ratio 5-hydroxymethylfurfural Levulinic acid Formic acid 36% % ⇌ C. B. Rasrendra et al. Top. Catal. 53, 15, (2010) A.M. Silva; E.C. da Silva; C.O. da Silva. Carbohydr. Res. 341, (2006) H. Wang; G. Gurau; R.D. Rogers; Chem. Soc. Rev. 41, (2012) F. Franks; J.R. Hall; D.E. Irish; K. Norris. Carbohydr. Res. 157, (1986)
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Noncovalent Carbohydrate Interactions
Problem: Difficult to characterize in solution Short lived Low concentrations Interference B.A. Cerda; C. Wesdemiotis. Int. J. Mass Spectrom. 189, (1999) A.L. Heaton; P.B. Armentrout. J. Phys. Chem. A 112, (2008)
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Noncovalent Carbohydrate Interactions
Problem: Difficult to characterize in solution Short lived Low concentrations Interference Solution: Isolate with mass spectrometer Preserves interactions Sensitive Selective via m/z of ion 172 – 181 kJ/mol Na+(Glucose) binding energy B.A. Cerda; C. Wesdemiotis. Int. J. Mass Spectrom. 189, (1999) A.L. Heaton; P.B. Armentrout. J. Phys. Chem. A 112, (2008)
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Noncovalent Carbohydrate Interactions
Problem: Difficult to characterize in solution Short lived Low concentrations Interference Solution: Isolate with mass spectrometer Preserves interactions Sensitive Selective via m/z of ion α β New problem: Difficult to characterize in gas phase SO MANY structures Which structures? Abundances? Gas-phase = solution-phase α:β? B.A. Cerda; C. Wesdemiotis. Int. J. Mass Spectrom. 189, (1999) A.L. Heaton; P.B. Armentrout. J. Phys. Chem. A 112, (2008)
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Noncovalent Carbohydrate Interactions
Problem: Difficult to characterize in solution Short lived Low concentrations Interference Solution: Isolate with mass spectrometer Preserves interactions Sensitive Selective via m/z of ion New problem: Difficult to characterize in gas phase SO MANY structures Which structures? Abundances? Gas-phase = solution-phase α:β? New Solution: Mass spec + IR spectroscopy Confirm structures Determine abundances Compare to solution B.A. Cerda; C. Wesdemiotis. Int. J. Mass Spectrom. 189, (1999) A.L. Heaton; P.B. Armentrout. J. Phys. Chem. A 112, (2008)
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Cryogenic Ion Vibrational Spectroscopy
Mass separation Mass selection Collisional cooling Tagged Ions Cooled Ions IR laser Frag. Ions Parent B.M. Marsh; J.M. Voss; E. Garand. J. Chem. Phys. 143 (2015)
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Cryogenic Ion Vibrational Spectroscopy
M+ M+·(D2) M+·(D2)2 2600 2800 3000 3200 3400 3600 3800 Photon Energy (cm -1 ) Mass gate on Laser on resonance (3550 cm-1)
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Na+Glucose Overview TOF
“Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Cryogenic Ion IR-IR Dip Spectroscopy
Time-of-Flight Tagging Trap M+·(D2) Signal decreases Laser on resonance (3550 cm-1) T.L. Guasco; B.M. Elliott; M.A. Johnson. J. Phys. Chem. Lett. 2010, 1, 2396–2401
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Na+Glucose Overview Trap TOF A Photon Energy (cm )
3300 3350 3400 3450 3500 3550 3600 3650 3700 3750 Photon Energy (cm -1 ) Trap 3300 3350 3400 3450 3500 3550 3600 3650 3700 3750 Photon Energy (cm -1 ) TOF A “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Na+Glucose Overview Trap TOF A A E J D F G B H I C Photon Energy (cm )
3300 3350 3400 3450 3500 3550 3600 3650 3700 3750 Photon Energy (cm -1 ) Trap 3300 3350 3400 3450 3500 3550 3600 3650 3700 3750 TOF A A E J D F G B H I C Photon Energy (cm -1 ) “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Na+Glucose IR-IR Dip & Subtraction
Harmonic spectra calculated with CAM-B3LYP/def2-tzvp F E β1 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Na+Glucose IR-IR Dip & Subtraction
Harmonic spectra calculated with CAM-B3LYP/def2-tzvp 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) F A E β1 β1 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) α0 “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Na+Glucose IR-IR Dip & Subtraction
3300 3400 3500 3600 3700 Photon Energy (cm -1 ) 8 conformers in 300 cm-1! Harmonic spectra calculated with CAM-B3LYP/def2-tzvp 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) α0 = A-β1 F A α1 = D-E α2 = C-D E β0 = H β1 β1 = F-E β2 = J-F β1 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) α0 β3 = B- α2 β4 = I-J “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Convolution and analysis
alpha beta α0 14 ±1% β0 16 ±3% α1 16 ±6% β1 18 ±1% α2 7 ±1% β2 6 ±1% α0 0 cm-1 β0 +957 cm-1 β1 532 cm-1 β3 10 ±3% β4 14 ±2% 36:64 α:β α1 +909 cm-1 β2 +1368 cm-1 β4 +2271 cm-1 α2 +687 cm-1 β3 +1081 cm-1 3300 3400 3500 3600 3700 Photon Energy (cm -1 ) Energies calculated with MP2/def2-tzvp “Structures of Na+(Glucose) adducts via cryogenic ion infrared spectroscopy.” (In preparation)
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Summary & Future Studies
Cryogenic Ion IR-IR Dip Spectroscopy More detailed information on structure and interactions Confirm structures Determine gas-phase populations Successfully samples solution Future Studies Glucose + Cl-, maltose + Cl- Garand Group Steve Kregel Kaitlyn Fischer Etienne Garand
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