Tuning the reactivity of dioxoruthenium(VI) porphyrins toward an arylimine by altering porphyrin substituants

Article abstract of DOI:10.1021/ic0484102

Reaction of dioxoruthenium(VI) porphyrins [Ru^VI(Por)O ₂] with arylimine HN=CPh₂ in dichloromethane afforded bis-(methyleneamido)ruthenium(IV) porphyrins [Ru^IV(Por)(N=CPh ₂)₂] for Por = 4-CI-TPP and TMP; (methyleneamido)- hydroxoruthenium(IV) porphyrins [Ru^VI(Por)(N=CPh₂)(OH)] for Por = TPP and TIP; and bis(arylimine)ruthenium(II) porphyrins [Ru ^II(Por)(HN=CPh₂)₂] for Por = 3,5-Cl ₂TPP and 3,5-(CF₃)₂TPP. In dichloromethane solution exposed to air, complex [Ru^II(3,5-Cl₂TPP)(HN= CPh₂)₂] underwent oxidative deprotonation.to form [Ru ^IV(3,5-Cl₂TPP)(N= CPh₂)₂]. The new ruthenium porphyrins were identified by ¹H NMR, UV-vis, IR, and mass spectroscopy, along with elemental analysis. X-ray crystal structure determinations of [Ru^IV(4-Cl-TPP)(N=CPh₂)₂], [Ru^IV(TPP)(N=CPh₂)-(OH)], and [Ru^II(3,5- (CF₃)₂TPP)(HN=CPh₂)₂] revealed the Ru-N(methyleneamido) or Ru-N(arylimine) distances of 1.897(5) A (average), 1.808(4) A, and 2.044(2) A (average), respectively.

Full text of DOI:10.1021/ic0484102

Inorg. Chem. 2005, 44, 3780−3788
Tuning the Reactivity of Dioxoruthenium(VI) Porphyrins toward an
Arylimine by Altering Porphyrin Substituents
Jie-Sheng Huang,* Sarana Ka-Yan Leung, Zhong-Yuan Zhou,† Nianyong Zhu, and Chi-Ming Che*
Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular
Technology for Drug DiscoVery and Synthesis, The UniVersity of Hong Kong,
Pokfulam Road, Hong Kong
Received November 11, 2004
Reaction of dioxoruthenium(VI) porphyrins [RuVI(Por)O2] with arylimine HN
(methyleneamido)ruthenium(IV) porphyrins [RuIV(Por)(N
CPh2)2] for Por
hydroxoruthenium(IV) porphyrins [RuIV(Por)(N
CPh2)(OH)] for Por TPP and TTP; and bis(arylimine)ruthenium(II)
porphyrins [RuII(Por)(HN
CPh2)2] for Por 3,5-Cl2TPP and 3,5-(CF3)2TPP. In dichloromethane solution exposed
to air, complex [RuII(3,5-Cl2TPP)(HN CPh2)2] underwent oxidative deprotonation to form [RuIV(3,5-Cl2TPP)(N
CPh2)2]. The new ruthenium porphyrins were identified by 1H NMR, UV
vis, IR, and mass spectroscopy, along
with elemental analysis. X-ray crystal structure determinations of [RuIV(4-Cl-TPP)(N CPh2)2], [RuIV(TPP)(N
CPh2)-
(OH)], and [RuII(3,5-(CF3)2TPP)(HN
CPh2)2] revealed the Ru N(methyleneamido) or Ru N(arylimine) distances
of 1.897(5) Å (average), 1.808(4) Å, and 2.044(2) Å (average), respectively.
d
CPh2 in dichloromethane afforded bis-
d
) 4-Cl-TPP and TMP; (methyleneamido)-
d
)
d
)
d
d
−
d
d
d
−
−
Introduction
thioethers,4a alcohols,4b and phosphines,4d,9a,b but also serves
as unique precursors for preparation of amine,4c,9d,e,17a-c
nitrosoarene,17f hydroxylamine,17f amido,17b,c hydrazido-
(1-),17d and imido17c complexes of ruthenium porphyrins.
Recently, we initiated exploration of the reactivity of
[RuVI(Por)O2] toward imines and obtained the bis-methyl-
Since the first synthesis of [RuVI(TMP)O2] (TMP ) meso-
tetramesitylporphyrinato dianion) by Groves and Quinn in
1984,1a dioxoruthenium(VI) porphyrins, [RuVI(Por)O2], have
received considerable attention.1-17 This interesting family
of high-valent ruthenium porphyrins not only exhibits high
reactivity toward oxidation of hydrocarbons,1b,2b-f,3,5,10,11,14,15
(5) (a) Higuchi, T.; Ohtake, H.; Hirobe, M. Tetrahedron Lett. 1989, 30,
6545. (b) Higuchi, T.; Ohtake, H.; Hirobe, M. Tetrahedron Lett. 1991,
32, 7435. (c) Ohtake, H.; Higuchi, T.; Hirobe, M. J. Am. Chem. Soc.
1992, 114, 10660. (d) Ohtake, H.; Higuchi, T.; Hirobe, M. Heterocycles
1995, 40, 867.
(6) Paeng, I. R.; Nakamoto, K. J. Am. Chem. Soc. 1990, 112, 3289.
(7) Schulz, L. D.; Fallon, G. D.; Moubaraki, B.; Murray, K. S.; West, B.
O. J. Chem. Soc., Chem. Commun. 1992, 971.
* To whom correspondence should be addressed. E-mail: cmche@hku.hk
(C.-M.C.); jshuang@hku.hk (J.-S.H.).
† Current address: Department of Applied Biology and Chemical
Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon,
Hong Kong.
(1) (a) Groves, J. T.; Quinn, R. Inorg. Chem. 1984, 23, 3844. (b) Groves,
J. T.; Quinn, R. J. Am. Chem. Soc. 1985, 107, 5790. (c) Groves, J. T.;
Ahn, K.-H. Inorg. Chem. 1987, 26, 3831.
(8) Tokita, Y.; Yamaguchi, K.; Watanabe, Y.; Morishima, I. Inorg. Chem.
1993, 32, 329.
(2) (a) Leung, W.-H.; Che, C.-M. J. Am. Chem. Soc. 1989, 111, 8812.
(b) Ho, C.; Leung, W.-H.; Che, C.-M. J. Chem. Soc., Dalton Trans.
1991, 2933. (c) Liu, C.-J.; Yu, W.-Y.; Peng, S.-M.; Mak, T. C. W.;
Che, C.-M. J. Chem. Soc., Dalton Trans. 1998, 1805. (d) Liu, C.-J.;
Yu, W.-Y.; Che, C.-M.; Yeung, C.-H. J. Org. Chem. 1999, 64, 7365.
(e) Zhang, R.; Yu, W.-Y.; Lai, T.-S.; Che, C.-M. Chem. Commun.
1999, 1791. (f) Zhang, R.; Yu, W.-Y.; Sun, H.-Z.; Liu, W.-S.; Che,
C.-M. Chem. Eur. J. 2002, 8, 2495.
(3) (a) Marchon, J.-C.; Ramasseul, R. J. Chem. Soc., Chem. Commun.
1988, 298. (b) Marchon, J.-C.; Ramasseul, R. Synthesis 1989, 389.
(c) Tavare`s, M.; Ramasseul, R.; Marchon, J.-C.; Bachet, B.; Brassy,
C.; Mornon, J. P. J. Chem. Soc., Perkin Trans. 2 1992, 1321.
(4) (a) Rajapakse, N.; James, B. R.; Dolphin, D. Catal. Lett. 1989, 2,
219. (b) Cheng, S. Y. S.; Rajapakse, N.; Rettig, S. J.; James, B. R. J.
Chem. Soc., Chem. Commun. 1994, 2669. (c) Bailey, A. J.; James, B.
R. Chem. Commun. 1996, 2343. (d) Cheng, S. Y. S.; James, B. R. J.
Mol. Catal. A: Chem. 1997, 117, 91.
(9) (a) Le Maux, P.; Bahri, H.; Simonneaux, G. J. Chem. Soc., Chem.
Commun. 1994, 1287. (b) Le Maux, P.; Bahri, H.; Simonneaux, G.;
Toupet, L. Inorg. Chem. 1995, 34, 4691. (c) Morice, C.; Le Maux,
P.; Simonneaux, G. Tetrahedron Lett. 1996, 37, 6701. (d) Morice,
C.; Le Maux, P.; Moinet, C.; Simonneaux, G. Inorg. Chim. Acta 1998,
273, 142. (e) Morice, C.; Le Maux, P.; Simonneaux, G.; Toupet, L. J.
Chem. Soc., Dalton Trans. 1998, 4165.
(10) Scharbert, B.; Zeisberger, E.; Paulus, E. J. Organomet. Chem. 1995,
493, 143.
(11) (a) Gross, Z.; Ini, S.; Kapon, M.; Cohen, S. Tetrahedron Lett. 1996,
37, 7325. (b) Gross, Z.; Ini, S. Inorg. Chem. 1999, 38, 1446. (c) Gross,
Z.; Ini, S. Org. Lett. 1999, 1, 2077.
(12) Leung, W.-H.; Hun, T. S. M.; Hou, H.-w.; Wong, K.-Y. J. Chem.
Soc., Dalton Trans. 1997, 237.
(13) Zobi, F.; Stynes, D. V. Can. J. Chem. 2001, 79, 795.
(14) Yamada, T.; Hashimoto, K.; Kitaichi, Y.; Suzuki, K.; Ikeno, T. Chem.
Lett. 2001, 268.
3780 Inorganic Chemistry, Vol. 44, No. 11, 2005
10.1021/ic0484102 CCC: $30.25
© 2005 American Chemical Society
Published on Web 02/22/2005

ReactiWity of Dioxoruthenium(VI) Porphyrins
Scheme 1
of simple imines are observed/proposed to be the intermedi-
ates in metal-mediated imine aziridination,21 imine/imide/
alkylidene metathesis,22 and amine-nitrile interconversion,23
isolation of bis-arylimine metalloporphyrins would be es-
sential for examination of their related reactivity, thus
facilitating development of metalloporphyrin-mediated
arylimine functionalizations or arylamine-nitrile intercon-
version.
In the course of our continuing studies on the reaction
between [RuVI(Por)O2] and imines, we have found that bis-
arylimine complexes [RuII(Por)(HNdCAr2)2] can be formed
and isolated in good yields from such reaction by employing
benzophenone imine (HNdCPh2) and certain porphyrin
ligands. Like the bis-arylamine analogues, a [RuII(Por)(HNd
CAr2)2] complex can undergo oxidative deprotonation,
leading to the formation of [RuIV(Por)(NdCAr2)2]. We have
also found that treatment of some [RuVI(Por)O2] complexes
with an arylimine afforded a (methyleneamido)hydroxoru-
thenium(IV) complex, [RuIV(Por)(NdCAr2)(OH)]. All these
findings are reported herein.
eneamido (or azavinylidene) metalloporphyrins, [RuIV(Por)-
(NdCAr2)2], from the reaction of [RuVI(TTP)O2] (TTP )
meso-tetrakis(p-tolyl)porphyrinato dianion) or [RuVI(3,4,5-
(MeO)3TPP)O2] (3,4,5-(MeO)3TPP ) meso-tetrakis(3,4,5-
trimethoxyphenyl)porphyrinato dianion) with arylimine.17e
This is similar to the formation of bis(arylamido)ruthenium-
(IV) porphyrins [RuIV(Por)(NHAr)2] or [RuIV(Por)(NAr2)2]
from treatment of [RuVI(Por)O2] with arylamine (such as
H2N-p-C6H4NO2 and HNPh2).17b,c However, reaction of
[RuVI(Por)O2] with arylamine (such as H2N-p-C6H4Cl) can
alsoaffordbis(arylamine)ruthenium(II)porphyrins[RuII(Por)(NH2-
Ar)2], which are readily convertible to bis(arylamido)-
ruthenium(IV) porphyrins through oxidative deprotonation.17c,18
It would be of interest to examine whether parallel reactivity
of [RuVI(Por)O2] toward arylimines, i.e., formation of bis-
(arylimine)ruthenium(II) porphyrins [RuII(Por)(HNdCAr2)2]
and oxidative deprotonation of the arylimine complexes to
give [RuIV(Por)(NdCAr2)2] (Scheme 1), can be observed.
Results and Discussion
Dioxoruthenium(VI) porphyrins [RuVI(Por)O2] can be
readily prepared by treatment of the carbonyl precursors
[RuII(Por)(CO)] with excess m-chloroperoxybenzoic acid.1,2a,b
It has been well documented that these ruthenium(VI)
complexes exhibit high reactivity toward a variety of alkyl-
or arylamines,4c,9d,e,17a-c affording, in most cases, bis(amine)-
ruthenium(II) porphyrins such as [RuII(Por)(H2NR)2] in high
yields. In contrast, much less is known about the reactivity
of [RuVI(Por)O2] toward alkyl- or arylimines; only the
reactions of a few [RuVI(Por)O2] complexes with 2,2,4,4-
tetramethylpentan-3-one imine (HNdCBut2)24 and HNd
So far there have been no reports (to our knowledge) on
bis-arylimine metalloporphyrins, despite previous isolation
of the bis-alkylimine analogues [RuII(Por)(EtNdCHMe)2]17e
and the mono-arylimine complex [RuII(Por)(CO)(PhNdCH-
p-C6H4Cl)].19 In general, metalloporphyrins with simple
imines, i.e., RNdCR′R′′ (R,R′R′′ ) alkyl or aryl), as the
sole axial ligands, are rare, and their synthetic route remains
elusive (see below), which is in contrast to the facile
formation of numerous pyridine, imidazole, or simple amine
complexes of metalloporphyrins.20 Since metal complexes
17e
CPh2 have been reported.
Reaction of [RuVI(Por)O2] with Arylimine. Following
our previous work on the reaction of [RuVI(TTP)O2] or
[RuVI(3,4,5-(MeO)3TPP)O2] with HNdCPh2,17e we examined
the reaction of [RuVI(Por)O2] with the same arylimine by
employing a series of other porphyrin ligands, including TPP
(meso-tetraphenylporphyrinato dianion) and its derivatives
4-Cl-TPP (meso-tetrakis(p-chlorophenyl)porphyrinato dian-
ion), TMP, 3,5-Cl2TPP (meso-tetrakis(3,5-dichlorophenyl)-
porphyrinato dianion), and 3,5-(CF3)2TPP (meso-tetrakis(3,5-
(15) Schwenninger, R.; Schlo¨gl, J.; Maynollo, J.; Gruber, K.; Ochsenbein,
P.; Bu¨rgi, H.-B.; Konrat, R.; Kra¨utler, B. Chem. Eur. J. 2001, 7, 2676.
(16) Funyu, S.; Isobe, T.; Takagi, S.; Tryk, D. A.; Inoue, H. J. Am. Chem.
Soc. 2003, 125, 5734.
(20) (a) Buchler, J. W. In Porphyrins and Metalloporphyrins; Smith, K.
M., Ed.; Elsevier: Amsterdam, 1975; p 157. (b) Buchler, J. W. In
The Porphyrins; Dolphin, D., Ed.; Academic: New York, 1978; Vol.
1, p 389. (c) Sanders, J. K. M.; Bampos, N.; Clyde-Watson, Z.; Darling,
S. L.; Hawley, J. C.; Kim, H.-J.; Mak, C. C.; Webb, S. J. In The
Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.;
Academic Press: San Diego, CA, 2000; Vol. 3, p 1. (d) Scheidt, W.
R. In The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard,
R., Eds.; Academic Press: San Diego, CA, 2000; Vol. 3, p 49.
(21) (a) Rasmussen, K. G.; Hazell, R. G.; Jørgensen, K. A. Chem. Commun.
1997, 1103. (b) Rasmussen, K. G.; Juhl, K.; Hazell, R. G.; Jørgensen,
K. A. J. Chem. Soc., Perkin Trans. 2 1998, 1347.
(22) Cantrell, G. K.; Meyer, T. Y. J. Am. Chem. Soc. 1998, 120, 8035.
(23) (a) Diamond, S. E.; Tom, G. M.; Taube, H. J. Am. Chem. Soc. 1975,
97, 2661. (b) Keene, F. R.; Salmon, D. J.; Meyer, T. J. J. Am. Chem.
Soc. 1976, 98, 1884. (c) Gunnoe, T. B.; White, P. S.; Templeton, J.
L. J. Am. Chem. Soc. 1996, 118, 6916.
(17) (a) Huang, J.-S.; Che, C.-M.; Poon, C.-K. J. Chem. Soc., Chem.
Commun. 1992, 161. (b) Huang, J.-S.; Che, C.-M.; Li, Z.-Y.; Poon,
C.-K. Inorg. Chem. 1992, 31, 1313. (c) Huang, J.-S.; Sun, X.-R.;
Leung, S. K.-Y.; Cheung, K.-K.; Che, C.-M. Chem. Eur. J. 2000, 6,
334. (d) Sun, X.-R.; Huang, J.-S.; Cheung, K.-K.; Che, C.-M. Inorg.
Chem. 2000, 39, 820. (e) Huang, J.-S.; Leung, S. K.-Y.; Cheung, K.-
K.; Che, C.-M. Chem. Eur. J. 2000, 6, 2971. (f) Liang, J.-L.; Huang,
J.-S.; Zhou, Z.-Y.; Cheung, K.-K.; Che, C.-M. Chem. Eur. J. 2001, 7,
2306.
(18) A non-porphyrin arylamine complex, [TpOsIII(NH2Ph)Cl2] (Tp )
hydrotris(pyrazolyl)borate), has also been reported to undergo oxidative
deprotonation to afford an arylamido complex, [TpOsIV(NHPh)Cl2],
see: (a) Soper, J. D.; Mayer, J. M. J. Am. Chem. Soc. 2003, 125,
12217. (b) Soper, J. D.; Rhile, I. J.; DiPasquale, A. G.; Mayer, J. M.
Polyhedron 2004, 23, 323.
(19) Li, Y.; Chan, P. W. H.; Zhu, N.-Y.; Che, C.-M.; Kwong, H.-L.
Organometallics 2004, 23, 54.
(24) Leung, S. K.-Y.; Huang, J.-S.; Liang, J.-L.; Che, C.-M.; Zhou, Z.-Y.
Angew. Chem., Int. Ed. 2003, 42, 340.
Inorganic Chemistry, Vol. 44, No. 11, 2005 3781

Huang et al.
Scheme 2
(trifluoromethyl)phenyl)porphyrinato dianion). This led to
the isolation of three types of ruthenium porphyrin prod-
ucts: [RuIV(Por)(NdCPh2)2] (Por ) 4-Cl-TPP: 1a, TMP:
1b), [RuIV(Por)(NdCPh2)(OH)] (Por ) TPP: 2a, TTP: 2b),
and [RuII(Por)(HNdCPh2)2] (Por ) 3,5-Cl2TPP: 3a, 3,5-
(CF3)2TPP: 3b) (Scheme 2).
The isolation of bis(methyleneamido)ruthenium(IV) por-
phyrins 1 for Por ) 4-Cl-TPP and TMP is similar to that
for Por ) TTP and 3,4,5-(MeO)3TPP reported previously.17e
In these cases, treatment of in situ formed [RuVI(Por)O2] with
excess HNdCPh2 in dichloromethane at room tempera-
ture followed by addition of ethanol to the reaction mix-
ture and subsequent evaporation of dichloromethane read-
ily gave 1 in about 65% yield as a dark purple, crystalline
solid.
(TPP)(NdCPh2)(OH)] (2a); the former was identified by its
1H NMR signals similar to those of [RuIV(TTP)(NdCPh2)2].25
Attempts to obtain pure [RuIV(TPP)(NdCPh2)2] were unsuc-
cessful. In an effort to purify the product by chromatography
on an alumina column, we found that [RuIV(TPP)(NdCPh2)2]
was transformed to 2a, which was isolated in 70% yield.
Complex 2a is a unique metalloporphyrin bearing both
methyleneamido and hydroxo axial groups. The facile
conversion of [RuIV(TPP)(NdCPh2)2] to 2a during the
chromatography prompted us to examine the stability of
previously reported [RuIV(TTP)(NdCPh2)2]17e toward similar
(25) 1H NMR spectral data for [RuIV(TPP)(NdCPh2)2] (300 MHz,
CDCl3): Hâ 8.46 (s, 8H), Ho 7.91 (d, J ) 7.8 Hz, 8H), Hm, Hp 7.67
(m, 12H), Hp′ 6.67 (t, J ) 7.5 Hz, 4H), H′ 6.44 (t, J ) 7.7 Hz, 8H),
m
Ho′ 4.03 (d, J ) 7.1 Hz, 8H). The signals of pyrrolic protons (Hâ) and
axial methyleneamido phenyl protons (H′p, H′ , and H′) are very
m
o
However, the same procedure for Por ) TPP led to the
similar to those reported for [RuIV(TTP)(NdCPh2)2]: Hâ 8.47 (s, 8H),
Hp′ 6.66 (t, 4H), H′ 6.43 (t, 8H), H′ 4.01 (d, 8H).17e
isolation of a mixture of [RuIV(TPP)(NdCPh2)2] and [RuIV-
m
o
3782 Inorganic Chemistry, Vol. 44, No. 11, 2005

ReactiWity of Dioxoruthenium(VI) Porphyrins
treatment, which resulted in almost complete conversion of
[RuIV(TTP)(NdCPh2)2] to [RuIV(TTP)(NdCPh2)(OH)] (2b).
1
The H NMR spectrum of 2b turned out to be virtually
identical to that of “[RuIV(TTP)(NdCPh2)]2O” previously
observed in solution;17e accordingly, the latter species should
be reformulated as [RuIV(TTP)(NdCPh2)(OH)] (see the
spectral and X-ray structural characterization of 2 described
below). Complexes 1a,b were found to be stable during the
chromatography.
It is interesting that reaction of [RuVI(3,5-Cl2TPP)O2] or
[RuVI(3,5-(CF3)2TPP)O2] with HNdCPh2, through a proce-
dure similar to that for preparation of 1a,b, afforded bis-
(arylimine)ruthenium(II) porphyrins 3a,b, which were iso-
lated in about 65% yield. This is parallel to the formation of
bis(amine)ruthenium(II) porphyrins from [RuVI(Por)O2] and
amines.4c,9e,17a-c
Figure 1. UV-vis spectra of [RuIV(TPP)(NdCPh2)(OH)] (2a) and
[RuII(3,5-Cl2TPP)(HNdCPh2)2] (3a) in CH2Cl2.
Besides 3a,b, the other known metalloporphyrins with
simple imine as the sole axial ligands are the bis-alkylimine
complexes [RuII(Por)(EtNdCHMe)2],17e which were prepared
through apparent N-dealkylation of triethylamine by [RuVI-
(Por)O2] (Scheme 2). Attempts to prepare bis(alkylimine)-
ruthenium(II) porphyrins from reaction of [RuVI(Por)O2] with
alkylimine HNdCBut2 were not successful; this reaction was
found to result in cleavage of the CdN bond and gave,
unexpectedly, nitridoruthenium(VI) complexes [RuVI(Por)-
(N)(OH)]24 (Scheme 2).
Spectral Characterization of Reaction Products. Bis-
(methyleneamido)ruthenium(IV) porphyrins 1a,b show UV-
vis spectra featuring Soret and â bands at about 420 and
530 nm, respectively, similar to those of [RuIV(TTP)(Nd
CPh2)2] and [RuIV(3,4,5-(MeO)3TPP)(NdCPh2)2].17e In the
1H NMR spectra, all these methyleneamido complexes
exhibit the axial [NdCPh2]- signals at δ ≈ 6.7 (t, H′), 6.4
p
(t, H′ ), and 4.0 ppm (d, H′), with the signal of pyrrolic
m
o
protons (Hâ) appearing at δ ≈ 8.5 ppm. The appearance of
a single set of the axial [NdCPh2]- phenyl signals arises
from the linear CdNsRusNdC arrangement in these
methyleneamido ruthenium(IV) porphyrins.17e
Complexes 1a,b, 2a,b, and 3b are moderately stable to
air both in the solid state and in solution, but complex 3a
can be handled only for a short time in solutions exposed to
air, although it is stable to air for weeks in the solid state.
Interestingly, when a solution of 3a in dichloromethane or
chloroform exposed to air was left standing for 1 day, this
complex was completely converted to the bis-methylene-
amido complex [RuIV(3,5-Cl2TPP)(NdCPh2)2], as revealed
Complexes 2a,b exhibit UV-vis spectra (Soret: ca. 420
nm, â: 527 nm) that are very similar to those of 1a,b and
[RuIV(TTP)(NdCPh2)2] but dramatically different from those
of previously reported dinuclear µ-oxo ruthenium(IV) por-
phyrins such as [RuIV(TPP)X]2O (X ) Cl-, ArO-).27 The
spectrum of 2a is shown in Figure 1 as an example. In the
1H NMR spectra of 2a,b (see, for example, Figure 2), all
the signals are located at normal fields and well resolved,
like those of diamagnetic complexes [RuIV(Por)(NdCPh2)2],17e
indicating the diamagnetic character of the (methyleneami-
do)hydroxoruthenium(IV) porphyrins. Because each [RuIV-
(Por)] moiety in 2a,b is unsymmetrically coordinated at the
axial sites, the ortho or meta protons of the meso-phenyl
groups in the porphyrin ligands give two well-separated sets
of peaks, in contrast to the single set of peaks observed for
such protons in [RuIV(TPP)(NdCPh2)2]25 and [RuIV(TTP)-
(NdCPh2)2].17e Also, the Hâ signals of 2a,b (δ ≈ 8.6 ppm)
are appreciably downfield from those of the two bis-
methyleneamido complexes. Since only a single set of the
axial [NdCPh2]- phenyl signals was observed for 2a,b, both
the complexes should contain linear axial Ru-NdC moi-
eties.
1
by H NMR and UV-vis spectroscopy.26
The reason for the marked dependence of the reactivity
of [RuVI(Por)O2] toward HNdCPh2 on the porphyrin sub-
stituents is not yet clear. It seems that electron-donating
substituents such as Me and MeO favor methyleneamido
ruthenium(IV) complexes whereas electron-withdrawing sub-
stituents such as CF3 favor arylimine ruthenium(II) com-
plexes. Indeed, electron-withdrawing substituents would
stabilize metal complexes in a lower oxidation state by
reducing the electron density of metal atoms. The conversion
of [RuIV(TPP)(NdCPh2)2] and [RuIV(TTP)(NdCPh2)2] to
2a,b through chromatography is probably due to the presence
of water in the alumina or solvents: we found that [RuIV-
(TTP)(NdCPh2)2] gradually converted to 2b in chloroform
solution exposed to air and addition of water to the solution
significantly speeded up the conversion. The higher stability
of 2a,b than [RuIV(TPP)(NdCPh2)2] and [RuIV(TTP)(Nd
CPh2)2] may be attributed to the stronger trans effect of the
methyleneamido group than the hydroxo group.
The UV-vis spectra of the bis(arylimine)ruthenium(II)
porphyrins 3a,b (see, for example, Figure 1) show Soret and
â bands at about 415 and 510 nm, respectively, which are
considerably blue shifted from those of 1a,b, but similar to
those of bis(amine)ruthenium(II) porphyrins.17a-c In the IR
(26) Spectral data for [RuIV(3,5-Cl2TPP)(NdCPh2)2], 1H NMR (300
MHz): Hâ 8.52 (s, 8H), Ho 7.80 (d, J ) 1.7 Hz, 8H), Hp 7.77 (t, J )
1.8 Hz, 4H); H′p 6.79 (t, J ) 7.4 Hz, 4H), H′ 6.51 (t, J ) 7.9 Hz,
m
8H), H′o 4.01 (d, J ) 7.1 Hz, 8H). UV-vis (CH2Cl2): λmax/nm 419
(Soret), 527 (â).
(27) Collman, J. P.; Barnes, C. E.; Brothers, P. J.; Collins, T. J.; Ozawa,
T.; Gallucci, J. C.; Ibers, J. A. J. Am. Chem. Soc. 1984, 106, 5151.
Inorganic Chemistry, Vol. 44, No. 11, 2005 3783

Huang et al.
Figure 2. 1H NMR spectrum of [RuIV(TPP)(NdCPh2)(OH)] (2a) in CDCl3 (the water came from the deuteriochloroform solvent).
Figure 3. 1H NMR spectrum of [RuII(3,5-(CF3)2TPP)(HNdCPh2)2] (3b) in CDCl3 (the water came from the deuteriochloroform solvent).
spectra of 3a,b, the oxidation state marker bands1c,17a appear
at frequencies of 1005 and 1002 cm-1, respectively, again
similar to those observed for the bis(amine)ruthenium(II)
porphyrins,17a-c but considerably lower than those of the
methyleneamido ruthenium(IV) porphyrins 1a,b and 2a,b
(1010-1012 cm-1) and bis(arylamido)ruthenium(IV) porphy-
rins.17b,c The weak and sharp bands at 3258 (3a) and 3250
cm-1 (3b) in the IR spectra are absent in the methyleneamido
complexes and can be attributed to the NH stretching
vibrations of the axial HNdCPh2 ligands.
[RuIV(3,5-Cl2TPP)(NdCPh2)2], the Hâ signal of the former
(δ ) 8.11 ppm) is significantly upfield from that of the latter
(δ ) 8.52 ppm).26
In the mass spectra of 3a,b, three cluster peaks assignable
to the parent ion [M]+, and the fragments [M - HNdCPh2]+
and [M - 2HNdCPh2]+ were observed in each case. For
1a,b, their mass spectral features are similar to the previously
reported analogues such as [RuIV(TPP)(NdCPh2)2].17e Com-
plexes 2a,b each exhibit a mass spectrum that is dominated
by the cluster peak ascribable to [M - OH]+; a cluster peak
assignable to [RuIV(Por)(NdCPh2)]2O (which might be
generated under the mass spectroscopic conditions) is also
present.
X-ray Crystal Structures. We have determined the crystal
structure of each type of the reaction products by employing
diffraction-quality crystals of 1a, 2a, and 3b‚0.5CH2Cl2. The
crystal data are summarized in Table 1. Selected bond
distances and angles are given in Table 2.
The structure of 1a (Figure 4) resembles that of [RuIV(3,4,5-
(MeO)3TPP)(NdCPh2)2] reported earlier,17e featuring a planar
Since the axial RusNdC moieties in 3a,b must be bent
and rotation of the CPh2 moiety of HNdCPh2 about its
CdN bond is prohibited, the two phenyl groups in each of
the axial HNdCPh2 ligands of 3a,b should give different
1
signals in the H NMR spectra. This is indeed found to be
the case (see, for example, the spectrum of 3b shown in
Figure 3), with one set of axial phenyl signals located at δ
≈ 7.2 (p-H), 6.7 (m-H), and 4.7 ppm (o-H), and the other at
δ ≈ 6.9 (p-H), 6.6 (m-H), and 4.3 ppm (o-H). Consistent
with the lower oxidation state of ruthenium in 3a than in
3784 Inorganic Chemistry, Vol. 44, No. 11, 2005

ReactiWity of Dioxoruthenium(VI) Porphyrins
Table 1. Crystallographic Data for [RuIV(4-Cl-TPP)(NdCPh2)2] (1a),
[RuIV(TPP)(NdCPh2)(OH)] (2a), and
[RuII(3,5-(CF3)2TPP)(HNdCPh2)2]‚0.5CH2Cl2 (3b‚0.5CH2Cl2)
1a
2a
3b‚0.5CH2Cl2
formula
C70H44Cl4N6Ru
C57H39N5ORu
C78H42F24N6Ru‚
0.5CH2Cl2
monoclinic
1662.71
P21/n
16.597(1)
17.904(2)
25.811(2)
90.00
cryst syst
fw
space group
a, Å
monoclinic
1211.98
P21/n
12.145(2)
20.470(4)
23.446(5)
90.00
monoclinic
911.00
P21/n
12.934(1)
30.942(4)
11.181(1)
90.00
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
102.48(3)
90.00
101.492(3)
90.00
93.517(2)
90.00
5691(2)
4
4384.9(8)
4
7656(1)
4
F
calc, g cm-3
1.415
1.380
1.443
2θ range, deg
50.90
55.12
55.20
GOF
R1/wR2
0.98
1.01
1.02
0.051/0.14
0.063/0.12
0.078/0.20
Figure 4. Structure of [RuIV(4-Cl-TPP)(NdCPh2)2] (1a) with omission
of hydrogen atoms (thermal ellipsoid probability: 30%).
Table 2. Selected Bond Distances (Å) and Angles (deg) for
[RuIV(4-Cl-TPP)(NdCPh2)2] (1a), [RuIV(TPP)(NdCPh2)(OH)] (2a), and
[RuII(3,5-(CF3)2TPP)(HNdCPh2)2]‚0.5CH2Cl2 (3b‚0.5CH2Cl2)
1a
Ru-N1
Ru-N3
Ru-N5
N5-C45
2.072(4)
2.060(4)
1.887(5)
1.198(6)
Ru-N2
Ru-N4
Ru-N6
N6-C58
2.051(4)
2.049(4)
1.906(4)
1.204(6)
N1-Ru-N2
N3-Ru-N4
N1-Ru-N3
N5-Ru-N1
N5-Ru-N3
N6-Ru-N1
N6-Ru-N3
N5-Ru-N6
C58-N6-Ru
89.1(2)
89.4(2)
179.8(2)
90.0(2)
90.0(2)
90.3(2)
89.8(2)
179.5(2)
174.1(4)
N2-Ru-N3
N1-Ru-N4
N2-Ru-N4
N5-Ru-N2
N5-Ru-N4
N6-Ru-N2
N6-Ru-N4
C45-N5-Ru
90.7(2)
90.8(2)
179.8(2)
90.1(2)
89.7(2)
90.3(2)
89.9(2)
175.3(4)
2a
Ru-N1
Ru-N3
Ru-N5
N5-C45
2.039(4)
2.051(4)
1.808(4)
1.274(5)
Ru-N2
Ru-N4
Ru-O1
2.045(4)
2.045(3)
1.971(3)
Figure 5. Structure of [RuIV(TPP)(NdCPh2)(OH)] (2a) with omission of
hydrogen atoms (thermal ellipsoid probability: 30%).
N1-Ru-N2
N3-Ru-N4
N1-Ru-N3
N5-Ru-N1
N5-Ru-N3
O1-Ru-N1
O1-Ru-N3
N5-Ru-O1
90.0(1)
90.5(1)
177.2(1)
93.0(2)
89.8(2)
88.6(1)
88.6(1)
178.3(2)
N2-Ru-N3
N1-Ru-N4
N2-Ru-N4
N5-Ru-N2
N5-Ru-N4
O1-Ru-N2
O1-Ru-N4
C45-N5-Ru
89.9(1)
89.5(1)
175.8(1)
93.0(2)
91.2(1)
87.7(1)
88.1(1)
175.0(4)
Complex 2a (Figure 5) contains a linear axial RusNdC
moiety (Ru-N-C 175.0(4)°) similar to that in 1a and
[RuIV(3,4,5-(MeO)3TPP)(NdCPh2)2], but shows appreciably
shorter Ru-N(axial) distance (1.808(4) Å) and longer
methyleneamido NdC distance (1.274(5) Å) than those of
the bis-methyleneamido complexes. This might arise from
a smaller trans influence of OH- than the methyleneamido
group, which results in the formation of stronger Ru-
N(axial) bond in the (methyleneamido)hydroxo complex. The
porphyrin ring in 2a is also planar, with a mean deviation
of 0.019 Å. The axial OsRusNdC moiety is linear (Os
RusN 178.3(2)°) and shows a RusO distance of 1.971(3)
Å.
Note that a methyleneamido group is isoelectronic with
the nitrosyl group, resembling the latter in binding metal
ions.28 In this context, the methyleneamido complexes [Ru-
(Por)(NdCPh2)2] and [Ru(Por)(NdCPh2)(OH)] may be
considered analogous to the nitrosyl complexes [Ru(Por)-
(NO)2] and [Ru(Por)(NO)(OH)], respectively. Since no [Ru-
3b‚0.5CH2Cl2
2.045(2)
2.046(2)
2.035(2)
1.291(3)
Ru-N1
Ru-N3
Ru-N5
N5-C53
Ru-N2
Ru-N4
Ru-N6
N6-C66
2.042(2)
2.040(2)
2.053(2)
1.310(3)
N1-Ru-N2
N3-Ru-N4
N1-Ru-N3
N5-Ru-N1
N5-Ru-N3
N6-Ru-N1
N6-Ru-N3
N5-Ru-N6
C66-N6-Ru
89.96(7)
89.96(7)
178.06(7)
81.69(7)
96.39(7)
97.46(7)
84.47(7)
176.87(7)
142.6(2)
N2-Ru-N3
N1-Ru-N4
N2-Ru-N4
N5-Ru-N2
N5-Ru-N4
N6-Ru-N2
N6-Ru-N4
C53-N5-Ru
90.40(6)
89.71(7)
178.98(7)
94.93(7)
85.99(7)
82.04(7)
97.04(7)
143.2(2)
porphyrin ring (mean deviation: 0.033 Å) and a linear axial
CdNsRusNdC moiety (C-N-Ru: 174.1(4)°, 175.3(4)°;
N-Ru-N: 179.5(2)°) with mean Ru-N distance of 1.897-
(5) Å and mean CdN distance of 1.201(6) Å (the corre-
sponding bond distances for [RuIV(3,4,5-(MeO)3TPP)(Nd
CPh2)2] are 1.896(8) and 1.25(1) Å17e).
(28) (a) Cotton, F. A.; Wilkinson, G. AdVanced Inorganic Chemistry, 5th
ed.; John Wiley & Sons: New York, 1988; p 371. (b) Johnson, B. F.
G.; Haymore, B. L.; Dilworth, J. R. In ComprehensiVe Coordination
Chemistry, Vol. 2; Wilkinson, G., Gillard, R. D., McCleverty, J. A.,
Eds.; Pergamon Press: Oxford, 1987; p 99.
Inorganic Chemistry, Vol. 44, No. 11, 2005 3785

Huang et al.
Figure 6. Comparison of the key bond distances (Å) and angles (deg) between [Ru(TPP)(NdCPh2)(OH)] (2a) and [Ru(TTP)(NO)(OH)].29 For clarity, the
meso-aryl groups of the porphyrin ligands are not shown.
(Por)(NO)2] species have been structurally characterized, nor
have structurally characterized methyleneamido complexes
of non-ruthenium metalloporphyrins been known, the struc-
ture determination of 2a, together with that of [Ru(TTP)-
(NO)(OH)],29 provides a unique opportunity to compare the
key structure features of methyleneamido- and nitrosylmet-
alloporphyrins.
As shown in Figure 6, there is indeed some similarity
between the structures of 2a and [Ru(TTP)(NO)(OH)].
Accordingly, an alternative formulation of 2a would be [RuII-
(TPP)(NdCPh2)(OH)] if one considers the methyleneamido
group as [NdCPh2]+, like the NO+ group in the nitrosyl
complex (which is usually formulated as [RuII(TTP)(NO)-
(OH)]). Figure 6 also shows that 2a exhibits slightly longer
RusN(axial) and RusO distances, along with a smaller
distortion (from planarity) of the porphyrin ring, than the
Figure 7. Structure of [RuII(3,5-(CF3)2TPP)(HNdCPh2)2]‚0.5CH2Cl2
nitrosyl complex, and the RusNdC moiety in 2a has a better
linearity than the RusNdO moiety in [Ru(TTP)(NO)(OH)].
Our previous work17e demonstrated that bis-methylene-
amido ruthenium porphyrins [Ru(Por)(NdCPh2)2] resemble
bis-arylamido ruthenium(IV) complexes [RuIV(Por)(NAr2)2]
or [RuIV(Por)(NHAr)2]. It seems that a methyleneamido
group has both the characters of nitrosyl and arylamido
groups. All these N-donor ligands can form RusN bonds
having significant multiple bonding characters.17e The shorter
RusN distance of Ru-NO in [Ru(TTP)(NO)(OH)] than that
of RusNdCPh2 in 2a, and the shorter RusN distances of
RusNdCPh2 in 1a than those of RusNHAr in [RuIV(TTP)-
(NHAr)2]17c reflect the order of RusN multiple bonding
characters: RusNO > RusNdCPh2 > RusNHAr.
In contrast to the linear axial RusNdC moieties in
methyleneamido complexes 1a and 2a, the bis-arylimine
complex 3b features bent axial RusNdC moieties (Figure
7) with average RusNsC angle of 142.9(2)°. The Rus
N(axial) distances of 2.035(2) and 2.053(2) Å in 3b are
substantially longer than those in 1a and 2a, but slightly
shorter than those of bis-alkylimine complex [RuII(TTP)-
(EtNdCHMe)2] (2.115(6) Å)17e and non-porphyrin arylimine
complex [RuII(Tp)(PEt3)2(HNdCPh2)]BPh4 (2.095(5) Å, Tp
) hydrotris(pyrazolyl)borate).30 A considerably longer Rus
N(axial) distance of 2.203 Å was observed for [RuII(Por)-
(3b‚0.5CH2Cl2) with omission of hydrogen atoms, except those on the
arylimine nitrogen atoms, and solvent molecule (thermal ellipsoid prob-
ability: 30%).
(CO)(PhNdCH-p-C6H4Cl)].19 All these alkyl- or arylimine
ruthenium complexes, including 3b, display the imine Cd
N distances within the narrow range 1.291(3)-1.310(3) Å.
The two phenyl groups in each of the axial ligands of 3b
make dihedral angles of about 20° and 89° with the porphyrin
plane, with one of the two phenyl groups being almost
perpendicular to the porphyrin plane, unlike the cases of 1a
and 2a (whose corresponding dihedral angles are about 48-
72°) but similar to the case of bis(hydrazido(1-))ruthenium-
(IV) porphyrin [RuIV(TTP)(HNNPh2)2] (which shows such
dihedral angles of about 10° and 85°).17d Moreover, the
porphyrin ring in 3b exhibits a marked saddle distortion with
mean deviation of 0.125 Å, a value considerably larger than
those of [RuII(TTP)(EtNdCHMe)2] (0.0241 Å) and the
foregoing methyleneamido complexes. Such a significant
distortion of the porphyrin ring in 3b might result from the
interaction between the phenyl groups of the arylimine and
the meso-aryl groups of the porphyrin ligand, analogous to
the case of [RuIV(TTP)(HNNPh2)2] (whose axial phenyl
groups are closer to the porphyrin ring and the porphyrin
ring atoms show a larger mean deviation of 0.167 Å from
(30) Jime´nez-Tenorio, M. A.; Jime´nez-Tenorio, M.; Puerta, M. C.; Valerga,
(29) Bohle, D. S.; Hung, C.-H.; Smith, B. D. Inorg. Chem. 1998, 37, 5798.
3786 Inorganic Chemistry, Vol. 44, No. 11, 2005
P. Inorg. Chim. Acta 2000, 300-302, 869.

ReactiWity of Dioxoruthenium(VI) Porphyrins
Figure 8. Comparison of the key bond distances (Å) and angles (deg) among [RuII(TTP)(EtNdCHMe)2],17e [RuII(3,5-(CF3)2TPP)(HNdCPh2)2] (3b), and
[RuIV(TTP)(HNNPh2)2].17d For clarity, the meso-aryl groups of the porphyrin ligands are not shown.
the mean plane).17d A comparison of the key structural
features among [RuII(TTP)(EtNdCHMe)2], 3b, and [RuIV-
(TTP)(HNNPh2)2] is depicted in Figure 8.
phyrins to both arylamido and nitrosyl analogues and
provides, to our knowledge, the first access to bis-arylimine
and (methyleneamido)hydroxo complexes of metalloporphy-
rins.
Conclusion
Experimental Section
The reactivity of dioxoruthenium(VI) porphyrins [RuVI-
(Por)O2] toward arylimine is affected by the substituents on
the meso-phenyl groups of the porphyrin ligands. Reaction
of in situ formed [RuVI(TPP)O2] with excess HNdCPh2
in dichloromethane affords a mixture of bis(methylene-
amido)ruthenium(IV) porphyrin [RuIV(TPP)(NdCPh2)2] and
(methyleneamido)hydroxoruthenium(IV) porphyrin [RuIV-
(TPP)(NdCPh2)(OH)]; the former can be converted to the
latter upon chromatography on an alumina column. Introduc-
ing 4-chloro, 2,4,6-trimethyl, or 3,4,5-trimethoxy substituents
to the meso-phenyl groups of the TPP macrocycle effectively
prevents formation of [RuIV(Por)(NdCPh2)(OH)], resulting
in the generation of stable [RuIV(Por)(NdCPh2)2] as the sole
isolable products. However, neither [RuIV(Por)(NdCPh2)2]
nor [RuIV(Por)(NdCPh2)(OH)] is observed when 3,5-di-
(trifluoromethyl) substituents are introduced; in this case, the
reaction product is bis(arylimine)ruthenium(II) porphyrin
[RuII(3,5-(CF3)2TPP)(HNdCPh2)2]. By introducing 3,5-
dichloro substituents, the product is a less stable bis-arylimine
complex [RuII(3,5-Cl2TPP)(HNdCPh2)2] which can be iso-
lated but, in solutions exposed to air, readily undergoes
oxidative deprotonation to form [RuIV(3,5-Cl2TPP)(Nd
CPh2)2], a reactivity resembling the formation of bis-
arylamine complex [RuII(Por)(NH2Ar)2] from [RuVI(Por)O2]
and NH2Ar and the oxidative deprotonation of [RuII(Por)(NH2-
Ar)2] to bis-arylamido complex [RuIV(Por)(NHAr)2] reported
earlier.17c X-ray crystal structure determination of [Ru(TPP)-
(NdCPh2)(OH)] reveals that the key structural feature of this
methyleneamido complex is similar to that of the nitrosyl
complex [Ru(TPP)(NO)(OH)]. The present work demon-
strates the resemblance of methyleneamido ruthenium por-
General. Benzophenone imine (97%, Aldrich) and m-chloro-
peroxybenzoic acid (m-CPBA; 55%, Merck) were used as received.
All solvents were of AR grade and were used without purification.
The complexes [RuII(Por)(CO)] (Por ) TPP, TTP, 4-Cl-TPP, TMP,
3,5-Cl2TPP, 3,5-(CF3)2TPP),31,32 used for in situ generation of [RuVI-
(Por)O2]33 (by oxidation with m-CPBA in dichloromethane), were
synthesized according to the literature method. UV-vis spectra were
recorded on a Hewlett-Packard 8453 diode array spectrophotometer
1
(interfaced with an IBM-compatible PC). H NMR spectra were
recorded on a Bruker DPX 300 spectrometer at 298 K with
tetramethylsilane (TMS) as internal standard. Chemical shifts (ppm)
are reported relative to TMS. IR spectra were obtained on a Bio-
Rad FT-IR spectrometer. Fast atom bombardment mass spectra
(31) Rillema, D. P.; Nagle, J. K.; Barringer, L. F., Jr.; Meyer, T. J. J. Am.
Chem. Soc. 1981, 103, 56.
(32) Spectral and analytical data for [RuII(3,5-Cl2TPP)(CO)], 1H NMR (300
MHz, CDCl3): Hâ 8.72 (s, 8H), Ho, H′ 8.13 (m, 4H), 8.05 (m, 4H),
o
Hp 7.81 (t, J ) 1.8 Hz, 4H). UV-vis (CH2Cl2): λmax/nm (log ꢀ) 413
(5.18), 529 (4.03). IR (Nujol): 1945 (νCO), 1010 cm-1 (oxidation state
marker band). Anal. Calcd for C45H20N4Cl8ORu‚H2O: C, 52.20; H,
2.14; N, 5.41. Found: C, 52.65; H, 2.31; N, 5.34. Spectral and
analytical data for [RuII(3,5-(CF3)2TPP)(CO)], 1H NMR (300 MHz,
CDCl3): Hâ 8.79 (s, 8H), Ho, H′ 8.63 (br, 8H), 8.36 (br, 4H). UV-
o
vis (CH2Cl2): λmax/nm (log ꢀ) 413 (5.23), 529 (3.96). IR (Nujol): 1921
(νCO), 1011 cm-1 (oxidation state marker band). Anal. Calcd for
C53H20N4F24ORu‚H2O: C, 48.82; H, 1.70; N, 4.30. Found: C, 49.12;
H, 1.78; N, 4.31.
(33) Treatment of [RuII(Por)(CO)] for Por ) 3,5-Cl2TPP and 3,5-(CF3)2-
TPP with m-CPBA in CH2Cl2 or CDCl3 completely shifted the Soret
(413 nm) and â (529 nm) bands (UV-vis spectra) to 421 and 519
1
nm, respectively, and the Hâ signal (δ ≈ 8.7 ppm, H NMR spectra)
to δ ≈ 9.1 ppm. This is characteristic of the conversion of the carbonyl
complexes to [RuVI(3,5-Cl2TPP)O2] or [RuVI(3,5-(CF3)2TPP)O2], like
the conversion of [RuII(Por)(CO)] with Por ) TPP, TTP, and 4-Cl-
TPP to the corresponding [RuVI(Por)O2] through similar reactions
(which shifts the Soret band from ca. 413 to 420 nm, the â band from
ca. 530 to 518 nm, and the Hâ signal from δ ≈ 8.6 to δ ≈ 9.1 ppm).2a,b
Inorganic Chemistry, Vol. 44, No. 11, 2005 3787

Huang et al.
1
(FAB MS) were recorded on a Finnigan MAT 95 mass spectrometer
using 3-nitrobenzyl alcohol as matrix. Electrospray mass spectra
(ES MS) were measured on a Finnigan LCQ quadrupole ion trap
mass spectrometer with HPLC dichloromethane as solvent. El-
emental analyses were performed by the Institute of Chemistry,
the Chinese Academy of Sciences.
Preparation of Bis(methyleneamido)ruthenium(IV) Porphy-
rins [RuIV(Por)(NdCPh2)2] (1). These complexes were isolated
as dark purple solids by treating [RuVI(Por)O2] (in situ formed from
[RuII(Por)(CO)] and m-CPBA) with excess HNdCPh2 (m-CPBA/
HNdCPh2 molar ratio ≈ 1:25) in dichloromethane according to a
procedure similar to that for the preparation of [RuIV(TTP)(Nd
CPh2)2] and [RuIV(3,4,5-(MeO)3TPP)(NdCPh2)2].17e
[RuII(3,5-Cl2TPP)(HNdCPh2)2] (3a). Yield: 63%. H NMR
(300 MHz, CDCl3): Hâ 8.11 (s, 8H), Ho 7.86 (d, J ) 1.9 Hz, 8H),
Hp 7.69 (t, J ) 1.8 Hz, 4H), H′, H′′ 7.16 (t, J ) 7.5 Hz, 2H), 6.83
(t, J ) 7.5 Hz, 2H), H′ , H′′ 6.74 (t, J ) 7.8 Hz, 4H), 6.58 (t, J )
p
p
m
m
7.8 Hz, 4H), H′, H′′4.71 (d, J ) 7.2 Hz, 4H), 4.30 (d, J ) 7.0 Hz,
o
o
4H). UV-vis (9.62 × 10-6 M, CH2Cl2): λmax/nm (log ꢀ) 415 (5.09),
512 (4.22). IR (KBr pellet): 3258 (νNH), 1005 cm-1 (oxidation state
marker band). FAB MS: m/z 1352 [M]+, 1171 [M - L]+, 990 [M
- 2L]+ (L ) HNdCPh2). Anal. Calcd for C70H42N6Cl8Ru: C,
62.19; H, 3.13; N, 6.22. Found: C, 62.41; H, 3.19; N, 5.99.
[RuII(3,5-(CF3)2TPP)(HNdCPh2)2] (3b). Yield: 65%. 1H NMR
(300 MHz, CDCl3): Hâ 8.03 (s, 8H), Ho 8.45 (s, 8H), Hp 8.23 (s,
4H), Hp′, H′′7.16 (t, J ) 7.7 Hz, 2H), 6.89 (t, J ) 7.7 Hz, 2H), H′ ,
p
m
[RuIV(4-Cl-TPP)(NdCPh2)2] (1a). Yield: 65%. 1H NMR (300
MHz, CDCl3): Hâ 8.46 (s, 8H), Ho 7.81 (d, J ) 8.4 Hz, 8H), Hm
7.63 (d, J ) 8.4 Hz, 8H), H′ 6.68 (t, J ) 7.5 Hz, 4H), H′ 6.43 (t,
Hm′′ 6.75 (t, J ) 7.8 Hz, 4H), 6.59 (t, J ) 7.8 Hz, 4H), H′, H′′ 4.76
o
o
(d, J ) 7.3 Hz, 4H), 4.39 (d, J ) 7.2 Hz, 4H). UV-vis (4.94 ×
10-6 M, CH2Cl2): λmax/nm (log ꢀ) 415 (5.24), 510 (4.33). IR (KBr
pellet): 3250 (νNH), 1002 cm-1 (oxidation state marker band). ES
MS (CH2Cl2): m/z 1620 [M]+, 1439 [M - L]+, 1258 [M - 2L]+
(L ) HNdCPh2). Anal. Calcd for C78H42N6F24Ru: C, 57.82; H,
2.61; N, 5.19. Found: C, 57.61; H, 2.90; N, 5.04.
p
m
J ) 7.7 Hz, 8H), H′o 3.98 (d, J ) 7.3 Hz, 8H). UV-vis (3.72 ×
10-6 M, CH2Cl2): λmax/nm (log ꢀ) 420 (5.37), 529 (4.28), 556 (3.99,
sh). IR (KBr pellet): 1010 cm-1 (oxidation state marker band). ES
MS: m/z 1212 [M]+, 1032 [M - L]+, 852 [M - 2L]+ (L ) Nd
CPh2). Anal. Calcd for C70H44N6Cl4Ru: C, 69.37; H, 3.66; N, 6.93.
Found: C, 69.65; H, 3.68; N, 6.68.
X-ray Crystal Structural Determination of 1a, 2a, and 3b‚
0.5CH2Cl2. Diffraction-quality crystals were grown by slow
evaporation of a solution in dichloromethane-hexane (1:5 v/v) at
room temperature for about 3 days (1a and 2a) or by slow
evaporation of a solution in dichloromethane-ethanol (1:5 v/v) at
room temperature for a week (3b‚0.5CH2Cl2). Data were collected
using graphite-monochromatized Mo KR radiation at 28 °C on a
MAR diffractometer with a 300-mm image plate detector for 1a
(dimensions 0.40 × 0.25 × 0.20 mm3) and at 21 °C on a Bruker
SMART CCD diffractometer for 2a (dimensions: 0.18 × 0.14 ×
0.08 mm3) and 3b‚0.5CH2Cl2 (dimensions: 0.20 × 0.16 × 0.14
mm3). In the case of 1a, the data collection was made with 2°
oscillation step of æ, 600-second exposure time, and 120-mm
scanner distance, and 100 images were collected. The structures
were solved by direct methods employing SIR-9734 program (1a)
or SHELXS-9735 program (2a and 3b‚0.5CH2Cl2) and refined by
full-matrix least-squares on F2 employing SHELXL-9736 program
on PC. For 3b‚0.5CH2Cl2, the F atoms of the CF3 groups in the
3,5-(CF3)2TPP ligand are disordered. In the least-squares refine-
ments, all non-hydrogen atoms, except some of the disordered F
atoms, were refined anisotropically, and the H atoms at calculated
positions were not refined.
[RuIV(TMP)(NdCPh2)2] (1b). Yield: 68%. 1H NMR (300 MHz,
CDCl3): Hâ 8.34 (s, 8H), Hm 7.12 (s, 8H), p-Me 2.55 (s, 12H),
o-Me 1.43 (s, 24H), H′ 6.64 (t, J ) 7.4 Hz, 4H), H′ 6.43 (t, J )
p
m
7.7 Hz, 8H), H′o 4.01 (d, J ) 7.3 Hz, 8H). UV-vis (4.94 × 10-6
M, CH2Cl2): λmax/nm (log ꢀ) 419 (5.24), 530 (4.27), 555 (3.92,
sh). IR (KBr pellet): 1012 cm-1 (oxidation state marker band).
FAB MS: m/z 1242 [M]+, 1062 [M - L]+, 882 [M - 2L]+ (L )
NdCPh2). Anal. Calcd C82H72N6Ru: C, 79.26; H, 5.84; N 6.76.
Found: C, 79.46; H, 6.03; N, 6.90.
Preparation of (Methyleneamido)hydroxoruthenium(IV) Por-
phyrins [RuIV(Por)(NdCPh2)(OH)] (2). These complexes were
prepared according to a similar procedure to that for the preparation
of 1, except that the products obtained were subjected to column
chromatography on alumina (aluminum oxide 90, neutral, 70-230
mesh, EM) with dichloromethane-chloroform as eluent followed
by removal of the solvents (which afforded 2 as dark purple solids).
1
[RuIV(TPP)(NdCPh2)(OH)] (2a). Yield: 70%. H NMR (300
MHz, CDCl3): Hâ 8.60 (s, 8H), Ho, Ho′ 8.27 (m, 4H), 7.82 (m,
4H), Hm, Hm′, Hp 7.73 (m, 8H), 7.66 (m, 4H), H′ 6.72 (t, J ) 7.4
p
Hz, 2H), Hm′ 6.55 (t, J ) 7.7 Hz, 4H), H′ 3.89 (d, J ) 7.4 Hz, 4H).
UV-vis (6.94 × 10-6 M, CH2Cl2): λmoax/nm (log ꢀ) 419 (5.29),
527 (4.23), 557 (3.81, sh). IR (KBr pellet): 3605 (νOH), 1012 cm-1
(oxidation state marker band). ES MS: m/z 894 [M - OH]+, 1805.
Anal. Calcd for C57H39N5ORu: C, 75.15; H, 4.31; N, 7.69. Found:
C, 75.55; H, 4.44; N, 7.67.
[RuIV(TTP)(NdCPh2)(OH)] (2b). Yield: 68%. 1H NMR (300
MHz, CDCl3): Hâ 8.61 (s, 8H), Ho, Ho′ 8.14 (dd, J ) 7.6, 1.7 Hz,
4H), 7.71 (dd, J ) 7.7, 1.8 Hz, 4H), Hm, Hm′ 7.54 (d, J ) 7.5 Hz,
Acknowledgment. This work was supported by The
University of Hong Kong, the Hong Kong University
Foundation, Hong Kong Research Grants Council (HKU7011/
04P), and the University Grants Committee of the Hong
Kong SAR of China (Area of Excellence Scheme, AoE/
P-10/01).
Supporting Information Available: Positional and thermal
parameters and bond lengths and angles for [RuIV(4-Cl-TPP)(Nd
CPh2)2] (1a), [RuIV(TPP)(NdCPh2)(OH)] (2a), and [RuII(3,5-(CF3)2-
TPP)(HNdCPh2)2]‚0.5CH2Cl2 (3b‚0.5CH2Cl2) in CIF format. This
material is available free of charge via the Internet at http://
pubs.acs.org.
4H), 7.47 (d, J ) 7.5 Hz, 4H), p-CH3 2.69 (s, 12H), H′ 6.69 (t, J
p
) 7.6 Hz, 2H), H′m 6.53 (t, J ) 7.7 Hz, 4H), H′ 3.87 (d, J ) 7.8
Hz, 4H). UV-vis (6.36 × 10-6 M, CH2Cl2): λmoax/nm (log ꢀ) 421
(5.28), 527 (4.32), 558 (4.11, sh). IR (KBr pellet): 3602 (νOH),
1011 cm-1 (oxidation state marker band). ES MS: m/z 950 [M -
OH]+, 1917. Anal. Calcd for C61H47N5ORu: C, 75.76; H, 4.90; N,
7.24. Found: C, 76.27; H, 4.84; N, 7.17.
IC0484102
Preparation of Bis(arylimine)ruthenium(II) Porphyrins [RuII-
(Por)(HNdCPh2)2] (3). These complexes were isolated as dark
purple solids according to the same procedure as that for the
preparation of 1a,b except that [RuII(3,5-Cl2TPP)(CO)] or [RuII(3,5-
(CF3)2TPP)(CO)] was used instead of [RuII(4-Cl-TPP)(CO)] or
[RuII(TMP)(CO)].
(34) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G.; Giacovazzo,
C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna, R. J.
Appl. Crystallogr. 1998, 32, 115.
(35) Sheldrick, G. M. SHELXS-97. Program for the Solution of Crystal
Structures; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
(36) Sheldrick, G. M. SHELXL-97. Program for the Refinement of Crystal
Structures; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
3788 Inorganic Chemistry, Vol. 44, No. 11, 2005