FORMAMIDE WATER AND THEIR COMPLEXES A MICROWAVE SPECTROSCOPY

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FORMAMIDE, WATER, AND THEIR COMPLEXES: A MICROWAVE SPECTROSCOPY STUDY SUSANA BLANCO JUAN CARLOS LÓPEZ

FORMAMIDE, WATER, AND THEIR COMPLEXES: A MICROWAVE SPECTROSCOPY STUDY SUSANA BLANCO JUAN CARLOS LÓPEZ Departamento de Química Física y Química Inorgánica Universidad de Valladolid, SPAIN GIER – Grupo de Investigación de Espectroscopía de Rotación ROTATIONAL SPECTROSCOPY RESEARCH GROUP http: //gier. blogs. uva. es/ CHANNING WEST MARTIN S. HOLDREN BROOKS PATE Department of Chemistry The University of Virginia, Charlottesville, VA, USA Pate’s Group http: //faculty. virginia. edu/bpate-lab/ 1

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide. WD WD Ca WD

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide. WD WD Ca WD C C N A A trans-peptide ~99% D Ca Ca D A N Ca WD A cis-peptide ~1% 2

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase of microsolvated clusters of simple molecules formamide - water formamide. 1: 1 clusters of formamide - water cover all possible hydrogen bond situations: S. Blanco et al. , JACS, J. Am. Chem. Soc. 2006, 128, 12111 R-Ca FW-1: 1 a Ca-R R-Ca Ca-R cis-peptide 42% in globular proteins FW-1: 1 c FW-1: 1 b trans-peptide 14% In globular proteins 3

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase of microsolvated clusters of simple molecules formamide - water formamide. 1: 2 formamide - water 1: 3 formamide - water 2: 1 formamide - water S. Blanco et al. , JACS, J. Am. Chem. Soc. 2006, 128, 12111 S. Blanco et al. , J. Phys. Chem. Lett. 2017, 6, 6060 S. Blanco et al. , Ang. Chem. Int. Ed. 2016, 55, 9331 FW-1: 2 a FW-1: 3 a FW-2: 1 4

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide – water: cooperative r.

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide – water: cooperative r. C-N = 1. 361 Å 1. 356 Å 1. 353 Å 1. 350 Å 1. 222 Å 1. 225 Å 1. 228 Å -3. 370 MHz effects 1. 341 Å 1. 342 Å 1. 231 Å 1. 232 Å 1. 231 Å -3. 080 MHz --2. 995 MHz -2. 976 MHz -2. 820 MHz -2. 97 MHz* 1. 343 Å r(C-N) decrease r. C=O = 1. 218 Å r(C=O) increase cc = -3. 854 MHz -3. 602 MHz -3. 47 MHz* cc variation f-w-b f-w-c f-w-a f-w 2 f 2 -w f-w 3 5

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide – water: cooperative effects

FORMAMIDE and WATER Peptide groups interactions may be modelled formamide – water: cooperative effects The electron density excess along the z axis in formamide progressively decreases as the number of molecules of water increase 6

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase

FORMAMIDE and WATER Peptide groups interactions may be modelled the study in gas phase of microsolvated clusters of simple molecules formamide - water W-5 FW-1: 3 a 7

FORMAMIDE and WATER MW spectra: CP-FTMW spectrometer 2 -8 GHz - 5/4 nozzle –

FORMAMIDE and WATER MW spectra: CP-FTMW spectrometer 2 -8 GHz - 5/4 nozzle – formamide (heated 60ºC) (14 N and 15 N) + Ne (4 bar) - 5/4 nozzle – formamide (heated 60ºC) (14 N and 15 N) + Ne – water (4 bar) Pate’s group (University of Virginia) 8

FORMAMIDE, WATER, AND THEIR COMPLEXES: A MICROWAVE SPECTROSCOPY STUDY SUSANA BLANCO JUAN CARLOS LÓPEZ

FORMAMIDE, WATER, AND THEIR COMPLEXES: A MICROWAVE SPECTROSCOPY STUDY SUSANA BLANCO JUAN CARLOS LÓPEZ Departamento de Química Física y Química Inorgánica Universidad de Valladolid, SPAIN GIER – Grupo de Investigación de Espectroscopía de Rotación ROTATIONAL SPECTROSCOPY RESEARCH GROUP http: //gier. blogs. uva. es/ CHANNING WEST MARTIN S. HOLDREN BROOKS PATE Department of Chemistry The University of Virginia, Charlottesville, VA, USA Pate’s Group http: //faculty. virginia. edu/bpate-lab/ 1