High-Energy Organic Molecules Caught in Frozen Matrices and Some Surprises

High-Energy Organic Molecules Caught in Frozen Matrices and Some Surprises 

Molecular nitrogen (N2) lacks a dipole moment and therefore does not absorb infrared radiation. Frozen nitrogen provides a suitable solid matrix for observing the IR spectra of exceedingly reactive intermediates. Similarly, argon has no bonds, no bond vibrations, and no IR spectrum. In 1973, Orville L. Chapman (1932-2004) at Iowa State generated the transient 1,2-benzyne (see chapter 6) in a solid argon matrix at 8 K (-445°F or -265°C) and recorded its IR spectrum. The spectrum was 

At Caltech Robert G. Bergman (1942- ) investigated 1,4-benzyne, an even less stable isomer of 1,2-benzyne. Synthesizing the deuterated compound (shown above), he heated it and observed it rearrange. A fairly simple combination of kinetic measurements and energy estimates indicated that 1,4-benzyne (see the structure a singlet having the two electrons paired) is a true chemical intermediate. This pure research study would have totally unexpected applications to cancer treatment in future decades (see chapter 9). 

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