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Chalyavi F, Schmitz AJ, Fetto NR, Tucker MJ, Brewer SH, Fenlon EE. Extending the vibrational lifetime of azides with heavy atoms. Phys Chem Chem Phys 2020; 22:18007-18013. [PMID: 32749405 DOI: 10.1039/d0cp02814b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The development of novel vibrational reporters (VRs), aka infrared (IR) probes, to study local environments and dynamic processes in biomolecules and materials continues to be an important area of research. Azides are important VRs because of their small size and large transition dipole strengths, however, their relatively short vibrational lifetimes (<2 ps) have limited their full potential. Herein we report that the vibrational lifetimes of azides can be increased by attaching them to heavy atoms and by using heavy 15N isotopes. Three group 14 atom triphenyl azides (Ph3CN3, Ph3SiN3, Ph3SnN3), and their triple-15N isotopomers, were synthesized in good yields. Tributyltin azide and its heavy isotopomer (Bu3Sn15N3) were also prepared to probe the effect of molecular scaffolding. The extinction coefficients for the natural abundance azides were determined, ranging from 900 to 1500 M-1 cm-1. The vibrational lifetimes of all azides were measured by pump-probe IR spectroscopy and each showed a major component with a short-to-moderate vibrational lifetime and a minor component with a much longer vibrational lifetime. Based on these results, the lifetime, aka the observation window, of an azide reporter can be extended from ∼2 ps to as long as ∼300 ps by a combination of isotopic labeling and heavy atom effect. 2D IR measurements of these compounds further confirmed the ability to observe these azide transitions at much longer timescales showing their utility to capture dynamic processes from tens to hundreds of picoseconds.
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Affiliation(s)
- Farzaneh Chalyavi
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Andrew J Schmitz
- Department of Chemistry, University of Nevada at Reno, Reno, NV 89557, USA.
| | - Natalie R Fetto
- Department of Chemistry, University of Nevada at Reno, Reno, NV 89557, USA.
| | - Matthew J Tucker
- Department of Chemistry, University of Nevada at Reno, Reno, NV 89557, USA.
| | - Scott H Brewer
- Department of Chemistry, Franklin & Marshall College, Lancaster, PA 17604, USA. ,
| | - Edward E Fenlon
- Department of Chemistry, Franklin & Marshall College, Lancaster, PA 17604, USA. ,
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Feng M, Zhao J, Yu P, Wang J. Linear and Nonlinear Infrared Spectroscopies Reveal Detailed Solute-Solvent Dynamic Interactions of a Nitrosyl Ruthenium Complex in Solution. J Phys Chem B 2018; 122:9225-9235. [PMID: 30200757 DOI: 10.1021/acs.jpcb.8b07247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In this work, the solvation of a nitrosyl ruthenium complex, [(CH3)4N][RuCl3(qn)(NO)] (with qn = deprotonated 8-hydroxyquinoline), which is a potential NO-releasing molecule in the bio-environment, was studied in two bio-friendly solvents, namely deuterated dimethyl sulfoxide (dDMSO) and water (D2O). A blue-shifted NO stretching frequency was observed in water with respect to that in dDMSO, which was believed to be due to ligand-solvent hydrogen-bonding interactions, one N═O···D and particularly three Ru-Cl···D, that show competing effects on the NO bond length. The dynamic differences of the NO stretch in these two solvents were further revealed by transient pump-probe IR and two-dimensional IR results: faster vibrational relaxation and faster spectral diffusion (SD) were observed in D2O, confirming stronger solvent-solute interaction and also faster solvent structural dynamics in D2O than in DMSO. Further, a significant non-decaying residual in the SD dynamics was observed in D2O but not in DMSO, suggesting the formation of a stable solvation shell in water due to strong multi-site ligand-solvent hydrogen-bonding interactions, which is in agreement with the observed blue-shifted NO stretching frequency. This work demonstrates that small solvent molecules such as water can form a relatively rigid solvation shell for certain transition metal complexes due to cooperative ligand-solvent interactions and show slower dynamics.
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Affiliation(s)
- Minjun Feng
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , P.R. China.,University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Juan Zhao
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , P.R. China.,University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Pengyun Yu
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , P.R. China.,University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
| | - Jianping Wang
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences , Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , P.R. China.,University of Chinese Academy of Sciences , Beijing 100049 , P.R. China
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Okuda M, Ohta K, Tominaga K. Rotational Dynamics of Solutes with Multiple Single Bond Axes Studied by Infrared Pump-Probe Spectroscopy. J Phys Chem A 2018; 122:946-954. [PMID: 29278912 DOI: 10.1021/acs.jpca.7b09939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To investigate the relationship between the structural degrees of freedom around a vibrational probe and the rotational relaxation process of a solute in solution, we studied the anisotropy decays of three different N3-derivatized amino acids in primary alcohol solutions. By performing polarization-controlled IR pump-probe measurements, we reveal that the anisotropy decays of the vibrational probe molecules in 1-alcohol solutions possess two decay components, at subpicosecond and picosecond time scales. On the basis of results showing that the fast relaxation component is insensitive to the vibrational probe molecule, we suggest that the anisotropy decay of the N3 group on a subpicosecond time scale results from a local, small-amplitude fluctuation of the flexible vibrational probe, which does not depend on the details of its molecular structure. However, the slow relaxation component depends on the solute: with longer alkyl chains attached to the N3 group, the anisotropy decay of the slow component is faster. Consequently, we conclude that the slow relaxation component corresponds to the reorientational motion of the N3 group correlated with other intramolecular rotational motions (e.g., rotational motions of the neighboring alkyl chain). Our experimental results provide important insight into understanding the rotational dynamics of solutes with multiple single bond axes in solution.
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Affiliation(s)
- Masaki Okuda
- Molecular Photoscience Research Center and ‡Graduate School of Science, Kobe University , Rokkodai-cho 1-1, Nada, Kobe 657-8501, Japan
| | - Kaoru Ohta
- Molecular Photoscience Research Center and ‡Graduate School of Science, Kobe University , Rokkodai-cho 1-1, Nada, Kobe 657-8501, Japan
| | - Keisuke Tominaga
- Molecular Photoscience Research Center and ‡Graduate School of Science, Kobe University , Rokkodai-cho 1-1, Nada, Kobe 657-8501, Japan
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