Inter‐Ring Interactions in Dimers of Magnesium π‐Cation Radicals: Control by Solvent Polarity
1997; Wiley; Volume: 36; Issue: 13-14 Linguagem: Inglês
10.1002/anie.199714561
ISSN1521-3773
AutoresK.E. Brancato-Buentello, W. Robert Scheidt,
Tópico(s)Metal-Catalyzed Oxygenation Mechanisms
ResumoAngewandte Chemie International Edition in EnglishVolume 36, Issue 13-14 p. 1456-1459 Communication Inter-Ring Interactions in Dimers of Magnesium π-Cation Radicals: Control by Solvent Polarity† Kristin E. Brancato-Buentello, Kristin E. Brancato-Buentello Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Search for more papers by this authorProf. W. Robert Scheidt, Corresponding Author Prof. W. Robert Scheidt Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Search for more papers by this author Kristin E. Brancato-Buentello, Kristin E. Brancato-Buentello Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Search for more papers by this authorProf. W. Robert Scheidt, Corresponding Author Prof. W. Robert Scheidt Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA), Fax: Int. code +(219)631-4044, e-mail: [email protected]Search for more papers by this author First published: August 4, 1997 https://doi.org/10.1002/anie.199714561Citations: 32 † This work was supported by the U. S. National Institutes of Health (GM-38401). K. E. B. thanks the J. Peter Grace Foundation for a doctoral fellowship. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Graphical Abstract ππ Stacking interactions stabilize the dimer (structure shown below on the left) that is formed from [Mg(oep.)]+ upon crystallization from CH2Cl2/CHCl3 (5/1). In contrast, crystallization from toluene/CH2Cl2 (4/1) gives a dimer whose porphyrin rings barely overlap (bottom right). The structural differences are attributed to the effect of solvent polarity. The solvent-dependence of the spectra is consistent with this interpretation. oep = octaethylporphyrin. References 1 J.-H. Fuhrhop, D. Mauzerall, J. Am. Chem. Soc. 1969, 91, 4174–4181. 2 J. Fajer, D. C. Borg, A. Forman, D. Dolphin, R. J. Felton, J. Am. Chem. Soc. 1970, 92, 3451–3459. 3 J.-H. Fuhrhop, P. Wasser, D. Riesner, D. Mauzerall, J. Am. Chem. Soc. 1972, 94, 7996–8001. 4 H. Song, C. A. Reed, W. R. Scheidt, J. Am. Chem. Soc. 1989, 111, 6867–6868. 5(a) H. Song, R. D. Orosz, C. A. Reed, W. R. Scheidt, Inorg. Chem. 1990, 29, 4274–4282; (b) W. R. Scheidt, H. Song, K. J. Haller, M. K. Safo, R. D. Orosz, C. A. Reed, P. G. Debrunner, C. E. Schulz, Inorg. Chem. 1992, 31, 939–941; (c) Inorg. Chem. 1997, 36, 406–412; (d) K. E. Brancato-Buentello, W. R. Scheidt, unpublished results. 6 Y. Murata, H. J. Shine, J. Org. Chem. 1969, 34, 3368–3372. 7 W. A. Oertling, A. Salechi, C. K. Chang, G. T. Babcock, J. Phys. Chem. 1987, 91, 3114–3116. 8 The EtOH molecule coordinated to Mg in crystals of 1 results from from the stabilizer in commercial CHCl3. Despite the importance of the EtOH in obtaining crystals, it has minimal effects on the spectra of a solution in CH2Cl2 at the small concentrations of the crystallization experiment. 9 Compound 1 crystallized from CH2Cl2/CHCl3 (ca. 5/1) layered with hexanes, and 2 from toluene CH2Cl2 (4/1). A pink-purple crystal of 1 (0.13 × 0.20 × 0.60 mm) and a dark purple crystal of 2 (0.017 × 0.06 × 0.17 mm) were analyzed on an Enarf-Nonius FAST area-detector diffractometer with a Mo rotating-anode source (λ = 0.71073 Å) by procedures that were described previously (W. R. Scheidt, I. Turowska-Tyrk, Inorg. Chem. 1994, 33, 1314–1318). Crystal data for 1: a = 12.176(1), b = 21.657(5), c = 29.302(8) Å, β = 99.94(1)°, monoclinic, P1, V = 7610.9(3) Å3, Z = 4 (dimers), ρcalcd = 1.291 gcm−3, 2θmax = 27.06°. Crystal data for 2: a = 10.280(4), b = 11.681(3), c = 13.939(6) Å, α = 83.93(2), β = 83.63(3), γ = 78.18(3)°, triclinic, P1, V = 1622.2(10) Å3, Z = 2, ρcalcd = 1.344 gcm−3, 2θmax = 29.73°. All measurements were made at 124±2 K. Data were corected for Lorentzian, polarization, and absorption factors (relative transmission coefficients = 1.00–0.729 for 1 and 1.00–0.565 for 2). Both strctures were solved by direct methods (SHELXS) [10a] and refined against F2 with SHELXL-93 [10b]. All data collected were used, and all porphyrin hydrogen atoms were idealized with the standard SHELXL-93 methods. 1: R1 = 0.0746 for 17417 observed reflections (Fo≥ 4.0σ(Fo)), wR2 = 0.2099 for 24123 total unique data (1884 variables refined) including negative F2 (residual electron density = 0.76 and −0.45 eÅ−3). 2: R1 = 0.1030 for 3993 observed data, wR2 = 0.2912 for 8081 unique data (463 variables; residual electron density = 063 and −0.71 eÅ−3). Crystallographic data (excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-100 099. Copies of the data can be obtained free of charge on application to The Director, CCDC, 12 Union Road, Cambridge CB21EZ, UK (fax: int. code +(1223) 336–033; e-mail: [email protected]). 10(a) G. M. Sheldrick, Acta Crystallogr. A 1990, 46, 467–473; (b) unpublished results. 11 W. R. Scheidt, Y. J. Lee, Struc. Bonding (Berlin) 1987, 64, 1–70. 12 K. E. Brancato-Buentello, S.-J. Kang, W. R. Scheidt, J. Am. Chem. Soc. 1997, 119, 2839–2846. 13(a) K. M. Barkigia, L. D. Spaulding, J. Fajer, Inorg. Chem. 1983, 22, 349–351; (b) C. C. Ong, V. McKee, G. A. Rodley, Inorg. Chim. Acta 1986, 123, L11–L14; (c) V. McKee, G. A. Rodley, Inorg. Chim. Acta 1988, 151, 233–236; (d) S. Yang, R. A. Jacobson, Inorg. Chim. Acta 1991, 190, 129–134. 14(a) R. Bonnett, M. B. Hursthouse, K. M. Abdul Malik, B. Mateen, J. Chem. Soc. Perkin Trans. 2 1977, 2072–2076; (b) V. McKee, C. C. Ong, G. A. Rodley, Inorg. Chem. 1984, 23, 4242–4248; (c) V. McKee, G. A. Rodley, Inorg. Chim. Acta 1988, 151, 233–236. 15 The effect of π complexation or π-π dimer formation on the out-of-plane position of the metal atom is that of a weakly interacting sixth ligand[4, 16]. 16 M. M. Williamson, C. L. Hill, Inorg. Chem. 1987, 26, 4155–4160. 17 J.-H. Fuhrhop, D. Mauzerall, J. Am. Chem. Soc. 1968, 90, 3875–3876. 18 M. Gouterman, J. Mol. Spectrosc. 1961, 6, 138–163. Citing Literature Volume36, Issue13-14August 4, 1997Pages 1456-1459 ReferencesRelatedInformation
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