2026-09-20T11:38:49Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/1542502026-06-05T15:29:57Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023
Sanford Miller.
Weinstein, Georgia Nan.
Massachusetts Institute of Technology. Department of Nutrition and Food Science.
Massachusetts Institute of Technology. Department of Nutrition and Food Science
2024-04-19T16:26:27Z
2024-04-19T16:26:27Z
1972
https://hdl.handle.net/1721.1/154250
1393108313
Thesis: M.S., Massachusetts Institute of Technology, Department of Nutrition and Food Science, 1972
Cataloged from the official PDF version of thesis. Vita.
Includes bibliographical references (pages 58-62).
Chapter I. Historical introduction to Vitamin B₆ Complexes. Chapter II. The aldimine complexes N(Salicylidene)glycinato and valinatozinc(II), N,~pyridoxylidene)valinatocopper(II) monohydrate and N-(3-Hydroxypyridyl-2-methylene)valinatocopper( II) hemihydrate have been prepared from L̳-valine. Synthetic methods and characterization data are given. Also prepared were the bis-chelate amino acid ester complexes, Bis[N- (2-ethoxycarbonyl-l-propyl)salicylaldiminato]copper(II) and Bis[N-(3-ethoxycarbonyl-2-propyl)salicylaldiminato]copper(II). The inertness of these two complexes to H-D exchange contrasts with the ready exchange in the absence of base of the complexes derived from a-amino acids. This result shows that facile exchange and racemization properties of Bis[N-(alkoxycarbonylalkyl)salicylaldimino] metal(II) complexes derive principally from the direct attachment of the electron-withdrawing HC=NM and COOC₂H₅ groups to the asymmetric center. The base-catalyzed racemization rates of four copper(II)-aldimine complexes in 95% ethanol at 50° were found to increase in the order N-Salicylidene-L̳-valinatocopper( II), Cu(sal-L̳-val) << N-Pyridoxylidene-L̳-valinatocopper(II) </- N-3-Hydroxypyridyl-2-methylene-L̳-valinatocopper(II) <N-4-NO₂ - Salicylidene-L̳-valinatocopper(II). This order is essentially the same as that of qualitative catalytic effectiveness of the constituent o̲-hydroxyarylcarbonyl compounds in nonenzyrnatic transamination and reinforces in semiquantitative fashion the prevailing model of ligand electronic features requisite to catalytic activity of these compounds.
by Georgia Nan Weinstein.
M.S.
M.S. Massachusetts Institute of Technology, Department of Nutrition and Food Science
64 pages
eng
Massachusetts Institute of Technology
MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.
http://dspace.mit.edu/handle/1721.1/7582
Nutrition and Food Science.
Metal complexes as models for vitamin B₆ catalysis
Thesis
application/pdf
2024-04-19T16:26:27Z
Publication
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<Abstract>Chapter I. Historical introduction to Vitamin B₆ Complexes. Chapter II. The aldimine complexes N(Salicylidene)glycinato and valinatozinc(II), N,~pyridoxylidene)valinatocopper(II) monohydrate and N-(3-Hydroxypyridyl-2-methylene)valinatocopper( II) hemihydrate have been prepared from L̳-valine. Synthetic methods and characterization data are given. Also prepared were the bis-chelate amino acid ester complexes, Bis[N- (2-ethoxycarbonyl-l-propyl)salicylaldiminato]copper(II) and Bis[N-(3-ethoxycarbonyl-2-propyl)salicylaldiminato]copper(II). The inertness of these two complexes to H-D exchange contrasts with the ready exchange in the absence of base of the complexes derived from a-amino acids. This result shows that facile exchange and racemization properties of Bis[N-(alkoxycarbonylalkyl)salicylaldimino] metal(II) complexes derive principally from the direct attachment of the electron-withdrawing HC=NM and COOC₂H₅ groups to the asymmetric center. The base-catalyzed racemization rates of four copper(II)-aldimine complexes in 95% ethanol at 50° were found to increase in the order N-Salicylidene-L̳-valinatocopper( II), Cu(sal-L̳-val) << N-Pyridoxylidene-L̳-valinatocopper(II) </- N-3-Hydroxypyridyl-2-methylene-L̳-valinatocopper(II) <N-4-NO₂ - Salicylidene-L̳-valinatocopper(II). This order is essentially the same as that of qualitative catalytic effectiveness of the constituent o̲-hydroxyarylcarbonyl compounds in nonenzyrnatic transamination and reinforces in semiquantitative fashion the prevailing model of ligand electronic features requisite to catalytic activity of these compounds.</Abstract>
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