Abstract
Metalloporphyrins are ubiquitous in nature, particularly iron porphyrins (hemes) and magnesium dihydroporphyrins or chlorophylls. Oxovanadium (IV) complexes of alkyl porphyrins are widely distributed in petroleum, oil shales and maturing sedimentary bitumen. Here we identify new vanadium compounds in Venezuela Orinoco heavy crude oil detected by Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). These compounds likely have the main structure of porphyrin, with the addition of more aromatic rings, thiophene and amino functional groups, corresponding to molecular series of C(n)H(2n-40)N(4)V(1)O(1) (36 ≤ n ≤ 58),C(n)H(2n-42)N(4)V(1)O(1) (37 ≤ n ≤ 57),C(n)H(2n-44)N(4)V(1)O(1) (38 ≤ n ≤ 59),C(n)H(2n-46)N(4)V(1)O(1) (43 ≤ n ≤ 54),C(n)H(2n-48)N(4)V(1)O(1) (45 ≤ n ≤ 55),C(n)H(2n-38)N(4)V(1)S(1)O(1) (36 ≤ n ≤ 41),C(n)H(2n-40)N(4)V(1)S(1)O(1) (35 ≤ n ≤ 51),C(n)H(2n-42)N(4)V(1)S(1)O(1) (36 ≤ n ≤ 54),C(n)H(2n-44)N(4)V(1)S(1)O(1) (41 ≤ n ≤ 55),C(n)H(2n-46)N(4)V(1)S(1)O(1) (39 ≤ n ≤ 55),C(n)H(2n-27)N(5)V(1)O(1) (29 ≤ n ≤ 40),C(n)H(2n-29)N(5)V(1)O(1) (34 ≤ n ≤ 42),C(n)H(2n-33)N(5)V(1)O(1) (31 ≤ n ≤ 38),C(n)H(2n-35)N(5)V(1)O(1) (32 ≤ n ≤ 41),C(n)H(2n-27)N(5)V(1)O(2) (32 ≤ n ≤ 41) and C(n)H(2n-29)N(5)V(1)O(2) (33 ≤ n ≤ 42). These findings are significant for the understanding of the existing form of vanadium species in nature, and are helpful for enhancing the amount of information on palaeoenvironments and improving the level of applied basic theory for the processing technologies of heavy oils.