isomerism

[i-som´ĕ-rizm]

the possession by two or more distinct compounds of the same molecular formula, each molecule having the same number of atoms of each element, but in different arrangement.

Chain isomerism. From Dorland's, 2000.

i·som·er·ism

(ī-som'ĕr-izm),

The existence of a chemical compound in two or more forms that are identical with respect to percentage composition but differ as to the positions of one or more atoms within the molecules, as well as in physical and chemical properties.

Farlex Partner Medical Dictionary © Farlex 2012

isomerism

Cardiology
A term referring to the development of right-sided and left-sided structures (e.g., the atria), on the right (termed right atrial isomerism), or left (termed left atrial isomerism) side.

Chemistry
The process by which one molecule is transformed into another with the same, albeit rearranged, atoms, which may occur spontaneously or require the input of energy.

Basic types of chemical isomerism:
• Structural isomerism, in which the isomers have the same chemical composition but differ from each other in the position (positional isomerism) of various molecules (e.g., of the halides—fluoride, chloride, bromide, etc.—or hydroxy groups), integral to their composition, as well as the integrity of their functional groups, which generally result in functional differences.

• Spatial isomerism, which is characterised by differences in geometric positioning of atoms and in which functional groups in space differ.

i·som·er·ism

(ī-som'ĕr-izm)

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

isomerism

the phenomenon of two chemical compounds having the same formula but a different arrangement of atoms.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Mentioned in

References in periodicals archive

Diagnosis and significance of atrial isomerism. Am J Cardiol 1986;58(3):342-346.

The peripartum management of a 32-year-old patient presenting at 34 weeks' gestation with unrepaired cyanotic heart disease

Schematic depiction of Azo-dopant undergoing Trans-Cis isomerism and perturb the order parameter of the aligned NLC host medium.

Multiple Time Scales Optical Nonlinearities of Liquid Crystals for Optical-Terahertz-Microwave Applications

[3] revealed the rotational isomerism of the end groups in rhodanine derivatives of merocyanines, which leads to four possible conformers, two of which are stable in cyclohexane.

Effect of concentration on isomerization of rhodanine derivatives of merocyanine dyes in polar solvents

Cann, "[sup.13]C nuclear magnetic resonance study of the cis-trans isomerism in X-Pro-Pro tripeptides," The Journal of Biochemistry, vol.

Study of a conformational equilibrium of lisinopril by HPLC, NMR, and DFT

Ramanathan, "Excited state relaxation dynamics of model green fluorescent protein chromophore analogs: Evidence for cis-trans isomerism," Journal of Physical Chemistry A, vol.

Detailed photoisomerization dynamics of a green fluorescent protein chromophore based molecular switch

Covering first metal complexes then transition metal chemistry, they discuss such topics as the correct empirical formula of complexes, isomerism and stereochemistry, metal carbonyls and nitrosyls, the vanadium group, and the actinides.

Coordination chemistry; metal complexes transition metal chemistry with lanthanides and actinides (a textbook for graduate and post graduate students of all Indian, Asian and foreign universities)

Evie has right atrial isomerism, a condition so rare that there are thought to be only two other cases in the UK.

EVIE'S A BACK TO FRONT MIRACLE; DIAGNOSED WITH HER INTERNAL ORGANS ROUND THE WRONG WAY, SURGEONS THOUGHT SHE WOULD NEVER SURVIVE THE WOMB..BUT LOOK AT HER NOW Miracle girl set to turn one

Presumablyinthe vicinity of 60[degrees]C, the aliphatic chains of the cross-linker undergo a cis-trans isomerism, or stiffening, making dislocation formation more difficult.

Polar liquid crystal elastomers cross linked far from thermodynamic phase transitions: dislocation loops in smectic clusters

She was born with left atrial isomerism with venous drainage of the lower body half via hemiazygos continuation to a single left superior caval vein.

Heart transplantation in congenital heart disease: in whom to consider and when?

Many reports, experimental [16-21]and theoretical [20, 22], show that acrylates and related compounds exhibit rotational isomerism with the planar s-trans and s-cis heavy-atom structures being the energetically most stable conformations.

Molecular structure and vibrational spectra of 2-ethylhexyl acrylate by density functional theory calculations