title: Selective breaking of bonds in water with intense, 2-cycle, infrared laser pulses.
abstract: One of the holy grails of contemporary science has been to establish the possibility of preferentially breaking one of several bonds in a molecule. For instance, the two O-H bonds in water are equivalent: given sufficient energy, either one of them is equally likely to break. We report bond-selective molecular fragmentation upon application of intense, 2-cycle pulses of 800 nm laser light: we demonstrate up to three-fold enhancement for preferential bond breaking in isotopically substituted water (HOD). Our experimental observations are rationalized by means of ab initio computations of the potential energy surfaces of HOD, HOD(+), and HOD(2+) and explorations of the dissociation limits resulting from either O-H or O-D bond rupture. The observations we report present a formidable theoretical challenge that need to be taken up in order to gain insights into molecular dynamics, strong field physics, chemical physics, non-adiabatic processes, mass spectrometry, and time-dependent quantum chemistry.
authors.affiliation: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors.forename: D
authors.initials: D
authors.lastname: Mathur
authors.affiliation: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors.forename: K
authors.initials: K
authors.lastname: Dota
authors.affiliation: Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India.
authors.forename: D
authors.initials: D
authors.lastname: Dey
authors.affiliation: Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Tiwari
authors.affiliation: Centre for Atomic and Molecular Physics, Manipal University, Manipal 576 104, India.
authors.forename: J A
authors.initials: JA
authors.lastname: Dharmadhikari
authors.affiliation: Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400 005, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Dharmadhikari
authors.affiliation: Saha Institute of Nuclear Physics, Bidhan Nagar, Kolkata 700 064, India.
authors.forename: S
authors.initials: S
authors.lastname: De
authors.affiliation: Department of Physics, Indian Institute of Technology Bombay, Mumbai 400 076, India.
authors.forename: P
authors.initials: P
authors.lastname: Vasa