The Structure Identification of Vanadium Porphyrins in Venezuela Crude Oil

The vanadium porphyrins were isolated from Venezuela crude oil. Meanwhile, ultraviolet-visible spectrophotometry and mass spectrometry were employed to characterize the vanadium porphyrins. The results indicate that the contents of ETIO and DPEP homologues in vanadium porphyrins of Venezuela crude oil are 80.7 and 19.3%, respectively. Furthermore, the C-28-ETIO shows the largest abundance in the ETIO homologues while the C-31-DPEP has the largest abundance in DPEP. The spatial structure calculation shows that the addition of metal vanadium destroys the overall structure of the porphyrin ring coplanarity. The coplanarity of the porphyrin ring is worse as there are more substituents (-CH2 or -CH3) connected with the porphyrin ring.