  Homonuclear correlation spectroscopy has played a crucial role in elucidating
structure of molecules in solution. In all kinds of homonuclear correlation,
the most intense peaks appear in the diagonal, and quite often due to its broad
dispersive tails obscure the useful cross peaks close to the diagonal. Herein,
we demonstrate that by editing the 1H magnetization by a C-13 nucleus in
natural abundance before starting the t1 evolution, it is possible to
discriminate the inphase 1H magnetizations that leads to the diagonal peaks
from the antiphase 1H magnetizations that generates the cross peaks. The 1H
magnetization is edited by a C-13 nucleus in natural abundance before starting
the t1 period in COSY. After the coherence transfer, the inphase transverse
magnetization directly attached to C-13 evolves under one bond heteronuclear
coupling for a time period 2{\tau} tuned to one bond heteronuclear coupling
while the antiphase transeverse magnetization directly attached to remote C-12
evolves under negligible long range heteronuclear couplings. As a result the
inphase magnetization can be eliminated as an unobservable heteronuclear
multiple quantum coherence leading to a diagonal free correlated spectrum. The
method is demonstrated for COSY.
