A New, Simple Route to Novel Gold Clusters - Brooklyn College ...

Figure 1. The structure of the cation of complex 6 in the crystal. Atomic
radii are arbitrary and H atoms are omitted for clarity. Selected bond
lengths [Š] and angles [8]: Ag1-Au1 2.8022(9), Ag1-Au2 2.797(1), Ag1-Au3
2.809(1), Au1-Au2 2.795(1), Au1-Au3 2.798(1); Au1-Ag1-Au2 59.97(3),
Au3-Ag1-Au1 60.21(3), Au2-Ag1-Au3 60.05(3).
deviate from the Au 6Ag plane by 0.75 Š, three lie above and
three below the plane.
The 1 H NMR spectrum of complex 6, as discussed above, is
in accordance withits structure being maintained in solution.
Thus, complexes 2 and 3 should present similar structures with
five gold ± mesityl fragments (indicated by their mass spectra).
In conclusion, the reaction sequence to generate 1 (Scheme
1 a) shows a general method to synthesize [(AuR) n]
complexes, which could be extended to other radical and/or
metallic centers. In addition, the preparation of 6 is a rare
example of template synthesis for a hexaatomic gold rim. We
are currently researching reactions with different organic
ligands and the effects of addition of different metallic ions to
these [AuR] n species.
Experimental Section
1: To a solution of (PPh3Bz)[Au(mes)Cl] [18] (0.5 mmol) in dichloromethane
(40 mL), a solution of [Ag(CF3SO3)] (0.5 mmol) in diethyl ether (10 mL) is
added. Precipitated AgCl was removed through celite filtration. The
solution was concentrated to about 2 mL and addition of diethyl ether
(30 mL) precipitated (BzPPh3)(CF3SO3), which was also removed by
filtration. Concentration of the solution to about 5 mL and addition of nhexane
(30 mL) afforded 1 as a pure solid (yield: 49 %).
2 and 3: To a diethyl ether solutions of 1 (0.25 mmol) 0.05 mmol of AgClO4 [or [Cu(CH3CN) 4]PF6] were added at 0 8C. Concentration of the deep green
[deep red] solution to about 5 mL and addition of n-hexane (20 mL)
precipitated 2 (yield: 40%) [3 (yield: 50 %)] as a green [red] solid.
Compounds 4 and 5 were obtained in 80 and 90%, respectively. The
reactions are similar to those previously reported for their mesityl
analogues. [18]
6: To a solution of 5 (0.25 mmol) in dichloromethane (30 mL), [Ag(CF3- SO3)] (0.042 mmol) was added. Preciptated AgCl was filtered. Addition of
of diethyl ether (30 mL) precipitated PPN(CF3SO3) which was also
separated by filtration. Concentration of the solution to about 5 mL and
addition of n-hexane (20 mL) afforded 6 as a deep green solid (40 %).
COMMUNICATIONS
Microcrystalline samples of complexes 1 ± 6 gave satisfactory elemental
analyses. Selected NMR data at room temperature ( 1H NMR: 300 MHz,
CDCl3, SiMe4; 31P{ 1H} NMR: 121 MHz, CDCl3, external 85 % H3PO4). 1:
1H: d ˆ 6.75 (s, 2H; m-H), 2.62 (s, 6 H; o-CH3), 2.14 (s, 3 H; p-CH3). 2: 1H: d ˆ 6.84 (s, 2 H; m-H), 2.76 (s, 6 H; o-CH3), 2.14 (s, 3H; p-CH3). 3: 1H: d ˆ
6.88 (s, 1 H; m-H), 6.86 (s, 1H; m-H), 2.67 (s, 3H; o-CH3), 2.63 (s, 3H; o-
CH3), 2.14 (s, 3 H; p-CH3). 4: 1H: d ˆ 7.59 ± 7.4 (m, 15 H), 6.97 (s, 2H), 3.6
(sept, 2 H, 2JH,H ˆ 6.9 Hz; o-CH(CH3) 2), 3.6 (sept, 1 H, 2JH,H ˆ 6.9 Hz; p-
CH(CH3) 2), 1.35 (d, 12H; CH3), 1.23 (d, 6 H; CH3). 5: 1H: d ˆ 7.64 ± 7.21 (m,
60H; PPN), 6.76 (s, 2 H), 3.81 (sept, 2H, 2JH,H ˆ 6.9 Hz; o-CH(CH3) 2), 2.74
(sept, 1H, 2JH,H ˆ 6.9 Hz; p-CH(CH3) 2), 1.16 (d, 18H; CH3); 31P{ 1H}: d ˆ
21.7 (s; PPN). 6: 1H: d ˆ 7.08 (s, 1 H), 6.78 (s, 1H), 3.91 (sept, 1H, 2JH,H ˆ
6.8 Hz; CH(CH3) 2), 3.08 (sept, 1 H, 2JH,H ˆ 6.8 Hz; CH(CH3) 2), 2.74 (sept,
1H, 2JH,H ˆ 6.8 Hz; CH(CH3) 2), 1.64 (d, 6H; CH3), 1.09 (d, 6H; CH3), 0.56
(d, 6 H; CH3). Crystal data for 6 ´ 1 2 CH2Cl2:C92H140AgAu6Cl2F3O3S, Mr ˆ 2743.67, triclinic,
space group P1Å, a ˆ 13.532(3), b ˆ 13.973(3), c ˆ 14.240(3) Š, a ˆ
90.93(3), b ˆ 105.4(3), g ˆ 95.89(3)8, V ˆ 2579.5(3) Š3 , Z ˆ 1, m ˆ
8.802 mm 1 , F(000) ˆ 1314, T ˆ 150 K. 32159 reflections were collected in
an Enraf ± Nonius Kappa CCD diffractometer, of which 9109 were
independent (Rint ˆ 0.060). Correction were made withthe SORTAV
program. [21] 33 distance restraints were applied to refine the positions of
two disordered isopropyl groups. Hydrogen atoms were placed in
calculated positions. The final wR(F 2 ) was 0.106 for 9109 data, 488
parameters, witha conventional R(F)[F 2 > 2s(F 2 )]ˆ 0.041. Max./min.
electron density ˆ 1.806/ 3.400 e Š3 . Crystallographic data (excluding
structure factors) for the structure reported in this paper has been
deposited with the Cambridge Crystallographic Data Centre as supplementary
publication no. CCDC-141781 (6). Copies of the data can be
obtained free of charge on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (fax: (‡ 44) 1223-336-033; e-mail: deposit@
ccdc.cam.ac.uk).
Received: March15, 2000 [Z 14855]
[1] B. K. Teo, H. Zhang, X. Shi, Inorg. Chem. 1994, 33, 4086, and
references therein.
[2] B. K. Teo, H. Zhang, X. Shi, J. Am. Chem. Soc. 1993, 115, 8489, and
references therein.
[3] T. G. M. M. Kappen, P. P. J. Schlebos, J. J. Bour, W. P. Bosman, G.
Beurskens, J. M. M. Smits, P. T. Beurskens, J. J. Steggerda, Inorg.
Chem. 1995, 34, 2121.
[4] T. G. M. M. Kappen, P. P. J. Schlebos, J. J. Bour, W. P. Bosman,
J. M. M. Smits, P. T. Beurskens, J. J. Steggerda, Inorg. Chem. 1994,
33, 754.
[5] R. C. B. Copley, D. M. P. Mingos, J. Chem. Soc. Dalton Trans. 1992,
1755.
[6] R. P. F. Kanters, P. P. J. Schlebos, J. J. Bour, W. P. Bosman, J. M. M.
Smits, P. T. Beurskens, J. J. Steggerda, Inorg. Chem. 1990, 29, 324.
[7] V. G. Albano, M. C. Iapalucci, G. Longoni, M. Monari, A. Paselli, S.
Zacchini, Organometallics 1998, 17, 4438.
[8] R. Uso n, A. Laguna, M. Laguna, B. R. Manzano, P. G. Jones, G. M.
Sheldrick, J. Chem. Soc. Dalton Trans. 1984, 285.
[9] R. Uso n, A. Laguna, M. Laguna, P. G. Jones, G. M. Sheldrick, J. Chem.
Soc. Chem. Commun. 1981, 1097.
[10] R. Uso n, A. Laguna, M. Laguna, P. G. Jones, C. F. Erdbrügger,
Organometallics 1987, 6, 1778.
[11] A. Burini, J. P. Fackler Jr., R. Galassi, B. R. Pietroni, R. J. Stapler,
Chem. Commun. 1998, 95.
[12] M. Contel, J. Garrido, M. C. Gimeno, M. Laguna, J. Chem. Soc. Dalton
Trans. 1998, 1083.
[13] S. Gambarotta, C. Floriani, A. Chiesi-Villa, C. Guastini, J. Chem. Soc.
Chem. Commun. 1983, 1304.
[14] E. M. Meyer, C. Floriani, A. Chiesi-Villa, C. Guastini, Organometallics
1989, 8, 1067.
[15] D. Belli-Dell Amico, F. Calderazzo, Gazz. Chim. Ital. 1973, 103, 1099.
[16] S. Gambarotta, C. Floriani, A. Chiesi-Villa, C. Guastini, J. Chem. Soc.
Chem. Commun. 1984, 870.
[17] R. Uso n, A. Laguna, E. J. FernaÂndez, M. E. Ruiz Romero, P. G. Jones,
J. Lautner, J. Chem. Soc. Dalton Trans. 1989, 2127.
Angew. Chem. Int. Ed. 2000, 39, No. 13 WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000 1433-7851/00/3913-2355 $ 17.50+.50/0 2355