steric hindrance

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ster·ic hin·drance

interference with or inhibition of a seemingly feasible reaction (usually synthetic) because the size of one or another reactant prevents approach to the required interatomic distance.
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
It can be imaged that the large anions would impose remarkable steric hindrance on the iron centers.
From a steric hindrance perspective, varying degrees of reactivity were anticipated and envisioned to follow the reactivity of the olefin on the POSS cage.
The T790M mutation leads to drug resistance by decreasing the binding of TKIs through steric hindrance and increasing EGFR's binding affinity for adenosine triphosphate.
Remarkably, resulting from its increased donor property and smaller steric hindrance between the thiophene and BPI unit (vide infra), the thienyl-containing dye (BPI-T) shows an apparent broadening especially for longer wavelength when compared to the phenylene-containing dye (BPI-P).
The adsorption of [H.sup.+] makes the micelles with positive charges and produces the electrostatic repulsion by the polar groups of the CTBA barrier and steric hindrance. On the other hand, CTAB has a large molecular size as a commonly used cationic surfactant.
Really long probes also don't work well; they have increased likelihood of binding to partial matches, and they can start to have physical steric hindrance or homodimer interactions, such as hairpin formation, that make them poorly available to interact with sample in the liquid phase.
Though the secondary amine can react with additional epoxide rings, as a result of steric hindrance and mixing constraints, residual hydrophilic amines (both primary and secondary) will be present in the film.
Finally, the 1,4 isomer has little steric hindrance or attractive forces affecting the rotation of the N[O.sub.2] groups.
High molecular weight and bulky molecules contributed to steric hindrance, thus preventing 2a-d from reaching the active site of enzyme [29].
Since both valine and phenylalanine are hydrophobic amino acids, these unfavorable interactions may cause a steric hindrance effect in the C2 domain, which may affect its stability or conformation and potentially its interaction with von Willebrand Factor (VWF) and/or phospholipids.
Scientists at the University of Kentucky tested their hypothesis that steric hindrance and interfacial myofibrillar proteins, when compared with the continuous phase, can more effectively protect oil droplets against oxidative changes.
The structure activity relationship (SAR) study demonstrated that complexation, steric hindrance, position of substituents, electron density around metal centre, hydrogen bonding and coordination mode of complexed ligands play prime role in modulating the biological activities of complexes.