\"Inorganic Chemist\" Ralph Pearson Hand Signed FDC Dated 1962 For Sale

Up for sale a RARE! "Inorganic Chemist" Ralph Pearson Hand Signed First Day Cover Dated 1962

ES-4065

Ralph Gottfrid Pearson (born January 12,

1919, Chicago) is a 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, when he

moved to University

of California at Santa Barbara (UCSB). He retired in 1989 but

remains active in research in theoretical inorganic chemistry. In 1963 he proposed the

qualitative theory of hard and soft acids and

bases (HSAB) in an attempt to unify the theories of reactivity

in inorganic and organic chemistry. In this theory 'Hard' applies to species

that are small, have high charge states, and are weakly polarizable. 'Soft' applies to species that are large, have

low charge states and are strongly polarizable. Acids and bases interact, and

the most stable interactions are hard-hard and soft-soft. In 1958 Pearson

and Fred Basolo, his colleague at Northwestern wrote the

influential monograph "Mechanisms of Inorganic concepts from ligand field theory and physical organic chemistry and

signaled a shift from descriptive coordination chemistry to

a more quantitative science. With another Northwestern colleague, Arthur

Atwater Frost, Pearson wrote in 1961 another classic text, Kinetics and

Mechanism: A Study of Homogeneous Chemical subsequent edition was with John W. Moore as co-author (ISBN 978-0471035589).

In 1983 in collaboration with Robert Parr, he refined the HSAB theory into a quantitative

method by calculating values of “absolute hardness” using density functional theory,

an approximate method in molecular quantum mechanics. This concept of

"absolute hardness" was later connected with the concept