Ethyl chlorophyllide

Figure 2.14 X-ray crystal structure of ethyl chlorophyllide show in the 5-coordinate Mg2+ ion.7...

Chow, H. C., Serlin, R., Strouse, C. E., Crystal and molecular structure and absolute configuration of ethyl chlorophyllide a-dihydrate. Model for the different spectral forms of chlorophyll a. J. Am. Chem. Soc. 1975, 97, 7230-7237. 

Pheophorblde. Replacement of the magnesium atom In chlorophyllide with hydrogen Ions results In the formation of olive-brown pheophorblde. The degradation of chlorophyllide a and b and their respective methyl and ethyl esters In acidified acetone was studied by Schanderl et al. (10). Substitution of lower molecular weight alcohols decreased sterlc hindrance from the C-7 side chain and Increased reaction rates. Ethyl-chlorophyllide a, methyl-chlorophyllide a, and chlorophyllide reaction 1.08, 1.42, and 1.56 times faster than chlorophyll a at 55°C. The t> derivatives of all chlorophyllldes reacted approximately 5 times slower at the same temperature. Dependence of reaction rate on temperature Is nearly unaffected by length of the C-7 side chain with activation energies of 10.4, 10.6, and 10.8 Kcals/mole reported between 25°C and 55 C, respectively for the 3 reactions. 

Fig. 7. One layer in the crystal structure of ethyl chlorophyllide

DiEtMeBPheod 4,5-diethyl methylbacteriopheophorbide d mesoporphyrin IX dimethyl ester Methyl Pheophorbide a Ethyl Chlorophyllide a or b Methyl Chlorophyllide a Methyl Pyrochlorophyllide a 3-vinyl-8-(E-2-nitrovinyl-l)deutero monoanion of 21-Methyl-5,10,15,20-tetraphenylporphyrin monoanion of 21-Phenyl-5,10,15,20-tetraphenylporphyrin dianion of 5,15-dimethyl-2,3,7,8,12,13,17,18-octaethylporphyrin... 

An example more representative of the type of molecule to which the FSGO basis is generally applied is ethyl chlorophyllide a (Et-Chl-a) [21], for which the FSGO basis set contains 239 basis functions (see Fig. 3 for molecular structure). With our current integral codes, thirty-four minutes of computer time are needed for integral... 

C37H26C0N4P, Corrole(triphenylphosphine)cobalt(lII), 42B, 374 C37H4oMgN40e, Ethyl chlorophyllide B dihydrate, 41B, 561 C37H42MgN407, Ethyl chlorophyllide A dihydrate, 41B, 562 C37H43FeN40s, Methoxyiron(III) mesoporphyrin-IX dimethyl ester, 30B, 218... 

Hydrogen bonding to the inner pyrrolic nitrogen atoms similar to that shown in Fig. 10 and extended tt-tt interactions have been observed also in crystal structures of 5,15-meso-disubstituted-diarylporphyrins by Sanders and co-workers [66,67]. It is noteworthy that in solutions of even weakly polar solvents (such as dichloromethane, chloroform) this association is not observable at room temperature, the solvated species being monomeric. Similarly, in ethyl chlorophyllide a, upon dissolution of the crystals the hydrogen bond network is disrupted, and the absorption spectrum becomes blue shifted, typical of monomeric Chi a. 

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