Succinic acid, formation constants with

The second relevant set of data is for the formation of the anhydride from substituted succinic acid derivatives. Equilibrium constants for the formation of the anhydride from the acid are available for the various methyl-substituted compounds (Table A.l) and the derived EM s are compared in Table 5 with those for intramolecular nucleophilic catalysis in the hydrolysis of half-esters... 

The equilibrium formation constants for the 1 1 complexes of Hf with glycine and serine in solutions of pH 2 have been determined as 31 and 18, respectively, and the HfO -amygdalic acid complex, [HfO PhCH(0)- 02)2] , has been obtained in aqueous solutions of pH 7—10.5. The stability constants of the 1 1 complexes of ZrO with iVh/ -ethylenediamine-bis(succinic acid) and Nh/ -ethylenediaminebis(glutaric acid) have been determined. ... 

Solution equilibrium studies410 have identified both 1 1 and 1 2 complexes found between V02+ ions and oxalic acid, but only 1 1 complexes for phthalic, maleic, succinic, and adipic acids. Equilibrium constants for the formation and subsequent hydrolysis of these complexes have been determined. VO(H2L) (H5L = trihydroxy-glutaric acid) is the principal complex species in mixed aqueous acetone solutions but minor amounts of (VO)3(H2L)2 are also formed 411 the stability of VO(H2L)-increases with increasing acetone content. Solvent effects are also evident in vana-dium(iv)-quercetin system 412 the protonated ligand RH2 forms VOR+ and VR2 + in methanol at pH 3 but only VOR+ in aqueous methanol. 

A number of simple carboxylic acids are known to be produced within the body, and so can be classed as endogenous ligands. Diacids such as fumaric, succinic, and malic acid are constantly synthesized and metabolized in cells during the Krebs cycle, whereas formic, oxahc, lactic, glutaric, and tartaric acid also play significant roles in biological processes (amino acids are discussed in Section 4.3). These endogenous linkers can be considered edible and have been extensively employed in MOF assembly—both transition metal and lanthanide formates with extended structures are commonplace, as well as... 

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