21-Thiatetra-p-tolylporphyrin and its copper(II) bicarbonate complex. Structural effects of copper-thiophene binding

Abstract

d-d bands due to the Ni2+ chromophore are consistent with a tetrahedral or distorted tetrahedral geometry,12 as is generally observed for metal ions bound to the native zinc site of this protein.1 Addition of azide to either of these derivatives causes no change in their spectra, consistent with the absence of a ligand-binding site on the Ni2+ ion when it is bound to the native zinc site. This behavior also is similar to that observed when other metal ions are bound to that site.The NMR spectra of Ag2Ni2SOD (Figure 2E) and of reduced Cu2Ni2SOD (Figure 2D) are also extremely similar.There are 15 detectable paramagnetically shifted proton NMR signals which we assign to the three histidyl and one aspartyl residues, which are presumably coordinated to Ni2+. By considering the line width (which is contributed by the distancedependent hyperfine interactions and chemical exchanges) of the isotropic shifts, the sharper signals can be tentatively assigned to Cj-H or N-H protons and the broad signals to Ce-H protons.3 We assign resonances, b, h, and j to N-H protons since they are not observed in D20. The upfield-shifted signals are tentatively assigned as Cj3-H2 protons of coordinated histidyl and aspartyl residues by comparison with paramagnetically shifted resonances of other proteins.3 Several other Ni2+-substituted derivatives of SOD have also been prepared in our laboratory. Their characterization and a fuller assignment of the NMR spectra of the above-described nickel derivatives are now in progress.Acknowledgment. Financial support from the USPHS (GM 28222) is gratefully acknowledged. We also thank Dr. James A. Roe for many helpful discussions.(12) Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chemistry, 4th ed.:

π Conjugation Transmitted across a d‐Electron Metallocene in Ferrocenothiaporphyrin Macrocycles

“…Significantly, in the dihydro derivative 6, the sign of the anisotropy is reversed, which is consistent with the presence of a diatropic current in the macrocycle. Indeed, the chemical shifts of peripheral protons on heterocyclic subunits are comparable with those reported for other porphyrinoids that display Hückel [20] or Möbius [11,18,21] aromaticity. This switching of the ring current sign upon formal two electron reduction/ oxidation is a typical feature of p-electron aromatic species.…”

Reactivity of Silole within a Core‐Modified Porphyrin Environment: Synthesis of 21‐Silaphlorin and its Conversion to Carbacorrole

“…[5,[22][23][24][25][26] Once arylaldehyde was included in the condensation, 5,10,15,20-tetraaryl-21-heteroporphyrins were produced as well. [5,6,8,[26][27][28] In the course of a typical synthesis in analogy to the formation of N-confused tetraarylporphyrin, [12,13] Nconfused heteroporphyrins were accompanied by formation of heteroporphyrins. [20,21] The use of X-confused derivatives 2,4-bis(arylhydroxymethyl)heterocyclopentadiene instead of a regular counterpart afforded X-confused heteroporphy-A C H T U N G T R E N N U N G rins.…”

Vibrational analysis of Ni(II) complex with 4,12-ditolyl-16,24-diphenyl-3-thiaporphyrin (SDTDPPNi(II)Cl) and its isotopic labeled (61Ni(II), −d6, and −d10) derivatives

“…The synthesis of freebase SDTDPPH was carried out according to the previously reported procedure [18,19]. The addition of NiCl 2 in methanol solution to a ligand in chloroform solution gave the five-coordinate SDTDPPNi(II)Cl [19,15].…”

“…, ν(C 46 -C 34 ) [7], ν(C 64 -C 17 ) [7], ν(C 60 -C 17 ) [7], δ(H 51 -C 46 -C 34 ) [5], δ(H 65 -C 64 -C 17 ) [ [11], δ(H 59 -C 49 -C 48 ) [18], δ(H 58 -C 48 -C 47 ) [10], δ(H 66 -C 63 -C 64 ) [11], δ(H 67 -C 62 -C 61 ) [18], δ(H 68 -C 61 -C 60 ) [10] 337-338 332 0 0 1183 δ(H 52 -C 50 -C 46 ) [11], δ(H 59 -C 49 -C 48 ) [19], δ(H 58 -C 48 -C 47 ) [10], δ(H 66 -C 63 -C 64 ) [11], δ(H 67 -C 62 -C 61 ) [19], δ(H 68 -C 61 -C 60 ) [10] 332 0 0 1155 1163 ν(C 10 -C 8 ) [8], ν(C 10 -C 7 ) [9], ν(C 8 -C 6 ) [8], δ(H 9 -C 8 -C 6 ) [5], δ(H 11 -C 10 -C 7 ) [ [9], ν(C 70 -C 72 ) [8], ν(C 41 -C 42 ) [8], ν(C 40 -C 44 ) [9], δ(H 77 -C 74 -C 72 ) [7], [9], ν(C 60 -C 61 ) [9], ν(C 47 -C 48 ) [9], ν(C 50 -C 46 ) [9], δ(H 59 -C 49 -C 48 ) [7], δ(H 67 -C 62 -C 61 ) [7] 242-248 133 1 0…”