Kamlet-Taft solvent parameters Parameters of the
Kamlet-Taft solvatochromic relationship that measure
separately the hydrogen bond donor (α), hydrogen
bond acceptor (β), and dipolarity/POLARIZABILITY(π*)
properties of solvents as contributing to overall solvent
POLARITY.
kappa convention SeeDONOR ATOM SYMBOL.
K capture Absorption of a K shell (n= 1) electron by
an atomic nucleus, where it combines with a proton as
it is converted to a neutron.
Kekulé structure (for aromatic compounds) A
representation of an AROMATIC MOLECULAR ENTITY
(such as benzene), with fixed alternating single and
double bonds, in which interactions between multiple
bonds are assumed to be absent.
For benzene:
are the Kekulé structures.
Kelvin The standard unit of thermodynamic temper-
ature. It is defined as 1/273.16 of the temperature of
the triple point of water above absolute zero. The sym-
bol for this is K. Kelvin is measured by the same tem-
perature steps as Celsius but is shifted downward so
that 0 K is absolute zero; water freezes at 273 K and
boils at 373 K.Kendall, Edward Calvin(1886–1972) American
Biochemist Edward Calvin Kendall was born on
March 8, 1886, in South Norwalk, Connecticut. He
was educated at Columbia University and obtained a
bachelor of science degree in 1908, a master’s degree in
chemistry in 1909, and a Ph.D. in chemistry in 1910.
From 1910 until 1911 he was a research chemist
for Parke, Davis and Co., in Detroit, Michigan, and
conducted research on the thyroid gland, continuing
the work from 1911 until 1914 at St. Luke’s Hospital,
New York City.
In 1914 he was appointed head of the biochemistry
section in the graduate school of the Mayo Foundation,
Rochester, part of the University of Minnesota. In 1915
he was appointed director of the division of biochem-
istry and subsequently professor of physiological chem-
istry. In 1951 he retired from the Mayo Foundation
and accepted the position of visiting professor in the
department of biochemistry at Princeton University.
In 1914 he isolated thyroxine, the active principle
of the thyroid gland. Kendall isolated and identified a
series of compounds from the adrenal gland cortex
and, with Merck & Co., Inc., prepared cortisone by
partial synthesis. He also investigated the effects of cor-153