The syntheses, characterization,
and reactivity of a series ofosmium porphyrins,Os
II(Por)(H
B>2NR)2 [Por =dianionsof octaethylporphyrinato (OEP), tetraphenylporphyrinato (TPP),meso-tetrakis(p-tolyl)porphyrinato(TTP), meso-tetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP),meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato(3,4,5-MeO-TPP), R = tBu; Por = TPP, R = iPr],OsII(Por)(HNEt2)2 (Por= TPP, 3,4,5-MeO-TPP),OsIV(Por)(NHAr)2 (Por= OEP, TPP, 3,4,5-MeO-TPP; Ar = Ph, 4-F-Ph),OsVI(Por)(NtBu)2 (Por = TPP,TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), OsVIO(Por)(NtBu) (Por = TPP, TTP,4-Cl-TPP, 3,4,5-MeO-TPP), and OsVIO(Por)(4-F-PhN)(Por = TPP,3,4,5-MeO-TPP) are described. The complexesOs(Por)(HNAr)2 are prepared from the reactions ofOs(Por)(N2)(THF) with arylamines in aerobic tetrahydrofuran.Air oxidations ofOs(Por)(H2NtBu)2 intetrahydrofuranand in the presence of H2NtBu giveOsO(Por)(NtBu) andOs(Por)(NtBu)2. The X-raycrystal structures of OsO(TTP)(NtBu)·EtOH andOs(4-Cl-TPP)(NtBu)2 have beendetermined. Crystal data forOsO(TTP)(NtBu)·EtOH:monoclinic, space group P21/c,a = 13.546(6) Å, b = 23.180(3) Å,c = 16.817(3) Å,
beta2.gif" BORDER=0 ALIGN="middle"> = 90.84(2)
,V = 5279.7(1.0) Å3, Z = 4.Os(4-Cl-TPP)(NtBu)2: monoclinic,space group P21/c, a =11.046(2) Å, b = 18.380(3) Å, c=23.640(4) Å,
beta2.gif" BORDER=0 ALIGN="middle"> = 97.22(1)
, V =4759.8(1.0) Å3, Z = 4. The Os=Oand Os=NtBu distances inOsO(TTP)(NtBu)·EtOH are 1.772(7) and 1.759(9)Å, respectively. The Os=NtBu distances inOs(4-Cl-TPP)(NtBu)2average1.775 Å. The imido angles range from 165.8(8) to170.6(9)
. For the infrared spectra of these complexes,adiscussion on the "oxidation state marker" band in the vicinity of1000 cm-1 is presented. The differencesin theelectronic properties of osmium porphyrins at various oxidation statesare also described.