TY - JOUR
T1 - Peripherally-metallated porphyrins
T2 - Meso-η1-porphyrinyl-platinum(II) complexes of 5,15-diaryl- and 5,10,15-triarylporphyrins
AU - Hartnell, Regan D.
AU - Edwards, Alison J.
AU - Arnold, Dennis P.
PY - 2002
Y1 - 2002
N2 - Attempted metathesis reactions of peripherally-metallated meso-η1-porphyrinylplatinum(II) complexes such as trans-[PtBr(NiDPP)(PPh3)2] (H2DPP = 5,15-diphenylporphyrin) with organolithium reagents fail due to competitive addition at the porphyrin ring carbon opposite to the metal substituent. This reaction can be prevented by using 5,10,15-triarylporphyrins, e.g. 5,10,15-triphenylporphyrin (H2TrPP) and 5-phenyl-10,20-bis(3',5'-di-t-butylphenyl)porphyrin (H2DAPP) as substrates. These triarylporphyrins are readily prepared using the method of Senge and co-workers by addition of phenyllithium to the appropriate 5,15-diarylporphyrins, followed by aqueous protolysis and oxidation. They are convenient, soluble building blocks for selective substitutions and subsequent transformations at the remaining free meso carbon. The sequence of bromination, optional central metallation and oxidative addition of Pt(0) tris(phosphine) complexes generates the organoplatinum porphyrins in high overall yields. The bromo ligand on the Pt(II) centre can be substituted by alkynyl nucleophiles, including 5-ethynylNiDPP, to form the first examples of meso-η1-porphyrinylplatinum(II) complexes with a second Pt-C bond. The range of porphyrinylplatinum(II) bis(tertiary phosphine) complexes was extended to the triethylphosphine analogues, by oxidative addition of H2TrPPBr to Pt(PEt3)3, and the initially-formed cis adduct is only slowly thermally transformed to trans-[PtBr(H2TrPP)(PEt3)2] 16. The molecular structures of NiDAPP 9b, trans-[Pt(NiDPP)(C2NiDPP)(PPh3)2] 14 and 16 were determined by X-ray crystallography.
AB - Attempted metathesis reactions of peripherally-metallated meso-η1-porphyrinylplatinum(II) complexes such as trans-[PtBr(NiDPP)(PPh3)2] (H2DPP = 5,15-diphenylporphyrin) with organolithium reagents fail due to competitive addition at the porphyrin ring carbon opposite to the metal substituent. This reaction can be prevented by using 5,10,15-triarylporphyrins, e.g. 5,10,15-triphenylporphyrin (H2TrPP) and 5-phenyl-10,20-bis(3',5'-di-t-butylphenyl)porphyrin (H2DAPP) as substrates. These triarylporphyrins are readily prepared using the method of Senge and co-workers by addition of phenyllithium to the appropriate 5,15-diarylporphyrins, followed by aqueous protolysis and oxidation. They are convenient, soluble building blocks for selective substitutions and subsequent transformations at the remaining free meso carbon. The sequence of bromination, optional central metallation and oxidative addition of Pt(0) tris(phosphine) complexes generates the organoplatinum porphyrins in high overall yields. The bromo ligand on the Pt(II) centre can be substituted by alkynyl nucleophiles, including 5-ethynylNiDPP, to form the first examples of meso-η1-porphyrinylplatinum(II) complexes with a second Pt-C bond. The range of porphyrinylplatinum(II) bis(tertiary phosphine) complexes was extended to the triethylphosphine analogues, by oxidative addition of H2TrPPBr to Pt(PEt3)3, and the initially-formed cis adduct is only slowly thermally transformed to trans-[PtBr(H2TrPP)(PEt3)2] 16. The molecular structures of NiDAPP 9b, trans-[Pt(NiDPP)(C2NiDPP)(PPh3)2] 14 and 16 were determined by X-ray crystallography.
KW - Crystal structure
KW - Organometallic
KW - Phosphine
KW - Platinum
KW - Porphyrin
UR - http://www.scopus.com/inward/record.url?scp=0036991179&partnerID=8YFLogxK
U2 - 10.1142/s1088424602000828
DO - 10.1142/s1088424602000828
M3 - Article
SN - 1088-4246
VL - 6
SP - 695
EP - 707
JO - Journal of Porphyrins and Phthalocyanines
JF - Journal of Porphyrins and Phthalocyanines
IS - 11-12
ER -