Mesoporphyrin IX dimethyl ester

The chromium(II) complex of mesoporphyrin IX dimethyl ester (276) can be prepared by metal insertion with an excess of chromium hexacarbonyl under nitrogen.1242 After removal of solvent and extinction with toluene, Crn(MPDME) is crystallized by the addition of n-pentane. Presumably the weakly acidic NH protons of the porphyrin oxidize Cr° to Cr11 and form H2. 

Figure 5 Typical mass spectrum (A.H.I. MS12) of mesoporphyrin-IX dimethyl ester (46). Note the typical fragmentation pattern of the propionic ester side chain at m/e 579 (-Me), 563 (-OMe), 535 (-C02Me) and 521 (-CH2C02Me)...

It is an unfortunate fact that, whereas many hundreds of materials have been used to form LB films, in the majority of cases no serious effort has been to characterise the film structure or even to show that a regular layer structure has been achieved. The example of amphiphilic porphyrins discussed above is sufficient to emphasise the need for proper characterisation. It will be recalled that mesoporphyrin IX dimethyl ester and the equivalent diol can, when complexed with a large variety of divalent metals, form excellent apparent Y layers with a deposition ratio very near unity on both up and down strokes. However, it is quite impossible to demonstrate the existence of a regular layer structure using X-ray diffraction techniques. Analogous situations involving two kinds of molecule will be discussed in Chapter S. 

Figure 5.18. (a) Mesoporphyrin IX dimethyl ester. (b) Mesoporphyrin IX diol. 

Table 3. Effect of axial ligands on the a- and fl-bands of Co(III) mesoporphyrin IX dimethyl ester )...

The rate constants for radiationless decay of the triplet state of mesoporphyrin IX dimethyl ester at 77 are 26 s-1 in EtOD and 57 s-1 in EtOH.352 The most probable cause is a decrease in the rate of tautomerism in the porphyrin due to deuteriation of the N—H hydrogen. However, for TPPH2 triplet state in n-octane matrices 363 such tautomerism does not appear to be an important mechanism for radiationless deactivation. Several recent reports deal with the low-temperature e.s.r. spectra of triplet states of porphyrins.364-368 The zero field splittings and depopulation rates of the various spin sub-levels of the triplet state of Zn-chlorophyll-a have been determined by an optically detected magnetic resonance method.359... 

Reaction of K2[OsCl6] or OsCl3 with meso(p-tolyl)porphyrin (HjTTP) with CO in the presence of pyridine yields Os(TTP)(CO)py which with pyridine gives Os(TTP)py2. On heating this gives a dimer [Os(TTP)]2 which presumably, like its OEP analogue, contains an Os=Os bond. A number of other complexes of the form Os(porphyrin)(CO)py can be obtained from K2[OsCl6], the porphyrin and CO in pyridine, e.g. mesoporphyrin-IX dimethyl ester, mesoporphyrin-XI dianion (I) and mesotetraphenylporphyrin the complex with (I) can also be made from Os3(CO)i2, pyridine and the porphyrin. ... 

Re2(CO)io reacts with meso-tetraphenylporphine in decalin under reflux to afford (meso-tetraphenylporphinato)bis tricarbonylrhenium(i) which has been shown by X-ray crystallography to involve the basic structural unit (92). Each Re atom is 142 pm out of the macrocyclic plane. The metal-metal separation of 312.6 pm is rather long for any direct interaction. Similar complexes containing two Re(CO)3 groups or one Re(CO)3 and one Tc(CO)3 group have been prepared with mesoporphyrin IX dimethyl ester. 

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... 

Higher pressure gas chromatography above critical temperatures has been used (Klesper et al 26) to separate nickel actio-porphyrin II and nickel mesoporphyrin IX dimethyl esters. Dichlorodifluoro-methane (critical temperature 112°) at a starting pressure of 1830 p.s.i. was used to separate the two nickel porphyrins in 1 mg quantities on a column of polyoxyethylene glycol (33%) on Chromosorb W at 150 to 170°C. The porphyrins do not move on the column at a gas pressure of less than 600 p.s.i. 

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... 

Figure 10 The combination of neutral laser desorption and resonance enhanced multiphoton ionization. A TOF mass spectrum of zinc mesoporphyrin-IX dimethyl ester is presented. Inset A the isotropic pattern (zinc, carbon) of the molecular ion. Inset ft the molecular ion of mesoporphyrin-IX dimethyl ester (TOF mass spectrum not shown) which displays the same isotope pattern as peak (M-64) due to loss of a zinc atom.

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