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HSAB theory is also useful in predicting the products of metathesis reactions. In 2005 it was shown that even the sensitivity and performance of explosive materials can be explained on basis of HSAB theory. [2] Ralph Pearson introduced the HSAB principle in the early 1960s [3] [4] [5] as an attempt to unify inorganic and organic reaction ...
In the theory of chemical reactivity, the Klopman–Salem equation describes the energetic change that occurs when two species approach each other in the course of a reaction and begin to interact, as their associated molecular orbitals begin to overlap with each other and atoms bearing partial charges begin to experience attractive or repulsive electrostatic forces.
Hard metal cations, as classified by HSAB theory, tend to form N-bonded complexes (isothiocyanates), whereas class B or soft metal cations tend to form S-bonded thiocyanate complexes. For the isothiocyanates, the M-N-C angle is usually close to 180°. For the thiocyanates, the M-S-C angle is usually close to 100°.
[2] [17] The Brønsted–Lowry acid–base theory was published in the same year. The two theories are distinct but complementary. A Lewis base is also a Brønsted–Lowry base, but a Lewis acid does not need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases (HSAB theory) followed in 1963.
Ralph Gottfrid Pearson (January 12, 1919 – October 12, 2022) was an American physical inorganic chemist best known for the development of the concept of hard and soft acids and bases (HSAB). He received his Ph.D. in physical chemistry in 1943 from Northwestern University , and taught chemistry at Northwestern faculty from 1946 until 1976 ...
In 1962, Edwards and Pearson (the latter of HSAB theory) introduced the phrase alpha effect for this anomaly. He offered the suggestion that the effect was caused by a transition state (TS) stabilization effect: on entering the TS the free electron pair on the nucleophile moves away from the nucleus, causing a partial positive charge which can be stabilized by an adjacent lone pair as for ...
Luche reduction is the selective organic reduction of α,β-unsaturated ketones to allylic alcohols. [1] [2] [3] The active reductant is described as "cerium borohydride", which is generated in situ from NaBH 4 and CeCl 3 (H 2 O) 7.
Before we explain this incorrectness, let us examine a little of the principles of HSABs: Pearson is the one who created the HSAB theory, based on the principle: Hard acids can react well with hard bases, amd soft acids with soft bases. The following is a table of common HSABs. Blnguyen (bananabucket) 03:53, 21 November 2006 (UTC)