Peter D. Jarowski

 

Postdoctoral fellow

Location:

HCI G-322

Phone:

+41-44-633 4171

e-mail:

Peter Jarowski

Education

1997-2002:

B. Sc. In Chemistry, NYU
Advisor: Prof. D. I. Schuster

2002-2006:

Ph. D. in Chemistry, UCLA
Advisors: Profs. K. N. Houk and Miguel A. Garcia-Garibay

2007-present:

Post-Doctoral Research, ETH-Zürich
Advisor: Dr. Prof. F. Diederich

New Cumulene Derivatives for Molecular Electronics and Non-Linear Optics Applications

Polyenes and polyynes have received much attention as potential components in molecular electronics (ME) and nonlinear optics (NLO). The conjugated carbon backbones of either act as excellent conductors and are potential nanoscopic molecular wires. Molecule based wires typically mediate communication between termini with donor and acceptor moieties. In ME the wire transports an electron from one end to the other, whereas in NLO the wire communicates instantaneous changes in local electromagnetic fields brought on by passing photons.
Cumulenes, another all carbon conjugated backbone, are not nearly as well studied as the analogous polyenes or polyynes despite intriguing theoretical predictions and some experimental results that suggest enhanced conducting properties. The technology for long polyenes has been available for some time and, more recently, the synthesis of longer polyynes has been achieved. In contrast, long cumulenes are still difficult to prepare. As a corollary, in particular, non-aliphatic or non-aromatic substitution of the cumulene core is rare, even for the short allene and 1,2,3-butatriene, i.e., hetero-atoms and functional groups. Thus, there is ample room for the synthesis of new cumulene derivatives. These derivatives may have enhanced stability, useful for the synthesis of longer cumulenes, modified electron affinity, and second- and third-order nonlinear response properties. Molecules with these enhancements may lead to materials in optical computing and laser technologies.
Longer Even C2n+2 cumulenes may also express very small internal rotational barriers since the terminal radicals are increasingly stabilized by delocalization along the main-chain (Scheme 1).


Scheme 1. Computed B3LYP/6-31G(d) structure and energies of the planar and perpendicular tetraethynyl[13]cumulene.

Barriers are further reduced by substitution with radical-stabilizing groups; experimental and computational rotational barriers for per-alkynylated butatrienes, e.g., are already at 20.0 kcal/mol (ΔG‡). With a combination of substitution and elongation cumulenes may become more stable in their perpendicular diradical states than in their planar forms (or these states may approach near degeneracy) giving rise to novel chromophores for NLO and ME applications.

Publications

T.-A. V. Khuong, H. Dang, P. D. Jarowski, E. Maverick, M. A. Garcia-Garibay, J. Am. Chem. Soc., 2007, 129, 839-845. Rotational Dynamics of a Molecular Gyroscope by Variable Temperature 13C NMR, 2H NMR, and X-Ray Diffraction Thermal Parameters.

P. D. Jarowski, F. Diederich, K. N. Houk, J. Am. Chem. Soc., submitted 2007. Stabilizing the Perpendicular Diradical of C2n + 2 Cumulenes by C2-Main-Chain-Expansion and Terminal Ethynyl Substitution.

M. D. Wodrich, C. S. Wannere, P. D. Jarowski, Y. Mo, P. v. R. Schleyer, K. N. Houk, Chem. Eur. J., accepted, 2007. The Concept of Protobranching and Its Many Paradigm Shifting Implications for Energy Evaluations.

P. D. Jarowski, K. N. Houk, M. A. Garcia-Garibay, J. Am. Chem. Soc. 2006, 129, 3110-3117. Importance of Correlated Motion on the Low Rotational Barriers within 1,4-bis(3,3,3-triphenyldipropynyl)benzene Clathrate and Desolvated Crystals.

P. D. Jarowski, F. Diederich, K. N. Houk, J. Phys. Chem. A 2006, 110, 7237-7246. Butatrienes as Extended Alkenes: Barriers to Internal Rotation and Substitution Effects on the Stabilities of the Planar Ground States and Perpendicular Transition States.

R. D. Horansky, L. I. Clarke, J. C. Price, S. D. Karlen, R. Santillan, P. D. Jarowski, M. A. Garcia-Garibay, Phys. Rev. B 2005, 74, 054306. Observation of Dipolar Rotor-Rotor Interactions in a Fluorobenzene Molecular Rotor Crystal.

P. D. Jarowski, Y. Mo, P. v. R. Schleyer, L. Song, K. N. Houk, J. Am. Chem. Soc., submitted, 2005. Searching for the Saturation Effect for Methyl Radicals Stabilized by One, Two, or Three Substituents.

R. D. Horansky, L. I. Clarke, J. C. Price, T.-A. V. Khuong, P. D. Jarowski, M. A. Garcia-Garibay, Phys. Rev. B 2005, 72, 014302-1 - 014302-5. Dielectric Response of a Dipolar Molecular Rotor Crystal.

P. D. Jarowski, F. Diederich, K. N. Houk, J. Org. Chem. 2005, 70, 1671-1678. Structures and Stabilities of Diacetylene-Expanded Polyhedranes by Quantum Mechanics and Molecular Mechanics.

D. I. Schuster, P. Cheng, P. D. Jarowski, D. M. Guldi, C. Luo, L. Echegoyen, S. Pyo, A. R. Holzwarth, S. E. Braslavsky, R. M. Williams, G. Klihm, J. Am. Chem. Soc. 2004, 126, 7257-7270. Design, Synthesis, and Photophysical Studies of a Porphyrin-Fullerene Dyad with Parachute Topology; Charge Recombination in the Marcus Inverted Region.

A. Auffrant, B. Jaun, P. D. Jarowski, K. N Houk, F. Diederich, Chem. Eur. J. 2004, 10, 2906-2911. Peralkynylated Buta-1,2,3-Trienes: Exceptionally Low Rotational Barriers of Cumulenic C=C Bonds in the Range of Those of Peptide C-N Bonds.

P. D. Jarowski, M. D. Wodrich, C. S. Wannere, P. v. R. Schleyer, K. N. Houk, J. Am. Chem. Soc. 2004, 126, 15036-15037. How Large is the Conjugative Stabilization of Diynes? Note: Article featured in C&EN news, December 20, 2004.

S. R. Wilson, S. MacMahon, F. T. Tat, P. D. Jarowski, D. I. Schuster, Chem. Comm. 2003, 2, 226-227. Synthesis and Photophysics of a Linear Non-Covalently Linked Porphyrin-Fullerene Dyad.

D. I. Schuster, J. Rosenthal, S. MacMahon, P. D. Jarowski, C. A. Alabi, D. M. Guldi, Chem. Comm., 2002, 21, 2538-2539. Formation and Photophysics of a Stable Concave-Convex Supramolecular Complex of C-60 and a Substituted s-Triazine Derivative.

D. I. Schuster, P. D. Jarowski, A. N. Kirschner, S. R. Wilson, J. Mat. Chem. 2002, 12, 2041-2047. Molecular Modelling of Fullerene-Porphyrin Dyads.

Last update: May 2007