Carbon-gold bond formation through [3 + 2] cycloaddition reactions of gold(I) azides and terminal alkynes

Article abstract of DOI:10.1021/om0607200

Carbon-gold bond formation propels a growing number of homogeneous catalyses, but the C-Au bond formation itself is comparatively underinvestigated. Reported here are C-Au bond-forming reactions that result from [3 + 2] cycloaddition of (triphenylphosphine)gold(I) azide to terminal alkynes. The reaction proceeds with the preformed azide complex or, in situ, by reaction of the corresponding gold(I) alkynyl with trimethylsilyl azide in the presence of protic solvents. This metal-mediated cycloaddition is analogous to the Huisgen dipolar addition of azides and alkynes and provides access to new classes of gold-bearing compounds and materials.

Full text of DOI:10.1021/om0607200

Organometallics 2007, 26, 183-186
183
Carbon-Gold Bond Formation through [3 + 2] Cycloaddition
Reactions of Gold(I) Azides and Terminal Alkynes
David V. Partyka,† James B. Updegraff III,† Matthias Zeller,‡ Allen D. Hunter,‡ and
Thomas G. Gray*,†
Departments of Chemistry, Case Western ReserVe UniVersity, 10900 Euclid AVenue, CleVeland, Ohio
44106, and Youngstown State UniVersity, 1 UniVersity Plaza, Youngstown, Ohio 44555
ReceiVed August 8, 2006
Carbon-gold bond formation propels a growing number of homogeneous catalyses, but the C-Au
bond formation itself is comparatively underinvestigated. Reported here are C-Au bond-forming reactions
that result from [3 + 2] cycloaddition of (triphenylphosphine)gold(I) azide to terminal alkynes. The
reaction proceeds with the preformed azide complex or, in situ, by reaction of the corresponding gold(I)
alkynyl with trimethylsilyl azide in the presence of protic solvents. This metal-mediated cycloaddition is
analogous to the Huisgen dipolar addition of azides and alkynes and provides access to new classes of
gold-bearing compounds and materials.
sign,13,14 and X-ray contrast imaging,15-17 among other pos-
sibilities.18,19
Metal-mediated cycloaddition chemistry is in an ascendancy
with the re-emergence of the Huisgen dipolar cycloaddition of
alkynes and azides,20 in the context of copper catalysis and the
Sharpless click chemistry.16-36 These reactions are believed to
Introduction
Carbon-gold bond formation recurs as an essential step in a
number of catalytic cycles, and organometallic catalysis with
gold reagents is growing explosively.1-4 However, rather little
attention has been given to gold-carbon bond-forming steps
per se.5-7 The gold(I)-carbon bond is in many cases stable to
air and water.8-10 The (phosphine)gold(I) fragment is isolobal
with H+, and (phosphine)- or (N-heterocyclic carbene)gold(I)
groups can act as functional groups in organic and other
molecules in place of protons. Foreseeable applications include
gold-driven catalysis, sensing,11,12 metallopharmaceuticals de-
(12) Luquin, A.; Baria´in, C.; Vergara, E.; Cerrada, E.; Garrido, J.; Matias,
I. R.; Laguna, M. Appl. Organomet. Chem. 2005, 19, 1232-1238.
(13) Shaw, C. F., III. Chem. ReV. 1999, 99, 2589-2600.
(14) Ho, S. Y.; Tiekink, E. R. T. In Metallotherapeutic Drugs & Metal-
based Diagnostic Agents: The Use of Metals in Medicine; Gielen, M.,
Tiekink, E. R. T., Eds.; Wiley: New York, 2005; pp 507-528.
(15) Yu, S.-B.; Watson, A. D. Chem. ReV. 1999, 99, 2353-2378.
(16) Hainfeld, J. F.; Slatkin, D. N.; Focella, T. M.; Smilowitz, H. M.
Brit. J. Radiol. 2006, 79, 248-253.
(17) Krause, W.; Schneider, P. W. Top. Curr. Chem. 2002, 222, 107-
150.
(18) Banaszak Holl, M. M.; Seidlerm, P. F.; Kowalczyk, S. P.; McFeely,
F. R. Inorg. Chem. 1994, 33, 510-517.
(19) Klassen, R. B.; Baum, T. H. Organometallics 1989, 8, 2477-2482.
(20) Huisgen, R.; Szeimes, G.; Moebius, L. Chem. Ber. 1967, 100, 2494-
2507.
* To whom correspondence should be addressed. E-mail: tgray@case.edu.
† Case Western Reserve University.
‡ Youngstown State University.
(1) Hoffmann-Ro¨der, A.; Krause, N. Org. Biomol. Chem. 2005, 3, 387-
391.
(2) Hashmi, A. S. K. Angew. Chem., Int. Ed. 2005, 44, 6990-6993.
(3) Hashmi, A. S. K. Gold Bull. 2004, 37, 51-65.
(4) For recent examples see: (a) Zhang, Z.; Liu, C.; Kinder, R. E.; Han,
X.; Qian, H.; Widenhoefer, R. A. J. Am. Chem. Soc. 2006, 128, 9066-
9073 and references therein. (b) Zhao, J.; Hughes, C. O.; Toste, F. D. J.
Am. Chem. Soc. 2006, 128, 7436-7437 and references therein. (c) Fructos,
M. R.; de Fre´mont, P.; Nolan, S. P.; D´ıaz-Requejo, M. M.; Pe´rez, P. J.
Organometallics 2006, 25, 2237-2241. (d) Zhang, J.; Yang, C.-G.; He, C.
J. Am. Chem. Soc. 2006, 128, 1798-1799. (e) Han, X.; Widenhoefer, R.
A. Angew. Chem., Int. Ed. 2006, 45, 1747-1749. (f) Nieto-Oberhuber, C.;
Lo´pez, S.; Echavarren, A. M. J. Am. Chem. Soc. 2005, 127, 6178-6179.
(g) Gazosz, F. Org. Lett. 2005, 7, 4129-4132. (h) Zhang, L.; Kozmin, S.
A. J. Am. Chem. Soc. 2004, 126, 11806-11807. (i) Luzung, M. R.;
Markham, J. P.; Toste, F. D. J. Am. Chem. Soc. 2004, 126, 10858-10859.
(j) Reetz, M. T.; Sommer, K. Eur. J. Org. Chem. 2003, 3485-3496.
(5) Ferna´ndez, E. J.; Laguna, A.; Olmos, M. E. AdV. Organomet. Chem.
2005, 52, 77-142.
(21) Tornøe, C. W.; Christensen, C.; Meldal, M. J. Org. Chem. 2002,
67, 3057-3064.
(22) Rostovtsev, V. V.; Green, L. G.; Fokin, V. V.; Sharpless, K. B.
Angew. Chem., Int. Ed. 2002, 41, 2596-2599.
(23) Kolb, H. C.; Finn, M. G.; Sharpless, K. B. Angew. Chem., Int. Ed.
2001, 40, 2004-2021.
(24) Himo, F.; Lovell, T.; Hilgraf, R.; Rostovtsev, V. V.; Noodleman,
L.; Sharpless, K. B.; Fokin, V. V. J. Am. Chem. Soc. 2005, 127, 210-216.
(25) Whiting, M.; Muldoon, J.; Lin, Y.-C.; Silverman, S. M.; Lindstrom,
W.; Olson, A. J.; Kolb, H. C.; Finn. M. G.; Sharpless, K. B.; Elder, J. H.;
Fokin, V. V. Angew. Chem., Int. Ed. 2006, 45, 1435-1439.
(26) Wang, Q.; Chan, T. R.; Hilgraf, R.; Fokin, V. V.; Sharpless, K. B.;
Finn, M. G. J. Am. Chem. Soc. 2003, 125, 3192-3193.
(27) Wu, P.; Malkoch, M.; Hunt, J. N.; Vestberg, R.; Kaltgrad, E.; Finn,
M. G.; Fokin, V. V.; Sharpless, K. B.; Hawker, C. J. Chem. Commun. 2005,
5775-5777.
(6) Schmidbaur, H. Organogold Compounds. In Gmelin Handbuch der
Anorganischen Chemie, 8th ed.; Slawisch, A., Ed.; Springer-Verlag: Berlin,
1980.
(7) Schmidbaur, H.; Grohmann, A.; Olmos, M. E. Organogold Chemistry.
In Gold: Progress in Chemistry, Biochemistry and Technology; Schmidbaur,
H., Ed.; Wiley: Chichester, U.K., 1999.
(8) Assefa, Z.; Forward, J. M.; Grant, T. A.; Staples, R. J.; Hanson, B.
E.; Mohamed, A. A.; Fackler, J. P., Jr. Inorg. Chim. Acta 2003, 352, 31-
45.
(28) Zhou, Z.; Fahrni, C. J. Am. Chem. Soc. 2004, 126, 8862-8863.
(29) Dichtel, W. R.; Miljanic´, O. Sˇ.; Spruell, J. M.; Heath, J. M.; Stoddart,
J. F. J. Am. Chem. Soc. 2006, 128, 10388-10390.
(30) Such, G. K.; Quinn, J. F.; Quinn, A.; Tjipto, E.; Caruso, F. J. Am.
Chem. Soc. 2006, 128, 9318-9319.
(31) Detz, R. J.; Heras, S. A.; de Gelder, R.; van Leeuwen, P. W. N.
M.; Hiemstra, H.; Reek, J. N. H.; van Maarseveen, J. H. Org. Lett. 2006,
8, 3227-3230.
(9) Forward, J. M.; Fackler, J. P., Jr.; Staples, R. J. Organometallics
1995, 14, 4194-4198.
(10) Mirkhalaf, F.; Paprotny, J.; Schiffrin, D. J. J. Am. Chem. Soc. 2006,
128, 7400-7401.
(32) Fleming, D. A.; Thode, C. J.; Williams, M. E. Chem. Mater. 2006,
18, 2327-2334.
(11) Yang, C.; Messerschmidt, M.; Coppens, P.; Omary, M. A. Inorg.
Chem. 2006, 45, 6592-6594.
(33) O’Reilley, R. K.; Joralemon, M. J.; Wooley, K. L.; Hawker, C. J.
Chem. Mater. 2005, 17, 5976-5988.
10.1021/om0607200 CCC: $37.00 © 2007 American Chemical Society
Publication on Web 12/06/2006

184 Organometallics, Vol. 26, No. 1, 2007
Partyka et al.
Scheme 1. Cycloaddition Reactions of Gold(I)a
Figure 1. Crystal structure of 5. Data were collected at 100 K;
50% probability ellipsoids are shown. Selected interatomic dis-
tances: C-Au, 2.027(5) Å; Au-P, 2.2710(13) Å; Ctriazolato-N,
1.357(7) Å. Selected angle: P-Au-C, 175.01(15)°.
affords 3 as the sole product in 87% isolated yield. Analogous
reactions of tert-butylacetylide and p-tolylacetylide complexes
with trimethylsilyl azide in the presence of CH3OH cleanly
delivers triazolates 4 and 5 in 85% and 90% isolated yields,
respectively. All new compounds have been characterized by
elemental analysis, multinuclear NMR, and X-ray diffraction
crystallography.
Diffraction-quality crystals were obtained by vapor diffusion
of pentane into a saturated THF/toluene solution of 2 or into
THF solutions of 3-5. Figure 1 depicts the structure of
compound 5; the structures of 2-4 appear in the Supporting
Information. In all instances, the 1,2,3-triazolato ligand is bound
a Isolated yields are indicated.
1
through carbon. An N-H resonance at δ ∼14 ppm in the H
occur by formation of a three-coordinate copper(I) acetylide that
reacts with an azide coligand, proceeding through a carbenoid
intermediate to yield a C-bound copper(I) triazolate. Protonation
at carbon affords the final 1,2,3-triazole.24 The uncatalyzed
reaction is concerted and can be induced by spatial confinement
of alkynes and azides in enzyme active sites.25
Recent precedents affirm the stability of the bond between
gold(I) and aryl or alkynyl carbon atoms in water.8-10 We find
that gold(I) is stably incorporated into organic molecules upon
reaction of (triphenylphosphine)gold(I) azide (1) with terminal
alkynes (Scheme 1). The reaction has clear potential for the
synthesis of gold organometallics from accessible gold(I) azides.
The cycloaddition superficially resembles the copper-catalyzed
chemistry, except that the gold-carbon linkage in the products
is hydrolytically stable and the organogold product is isolated.
NMR spectrum confirms that the carbon-bound structure is
maintained in solution. Gold-carbon lengths, which vary from
2.002(9) Å (4) to 2.027(5) Å (5), and the range of gold-
phosphorus bond distances, 2.2641(15) and 2.2677(15) Å (2,
both crystallographically independent molecules) to 2.279(2)
Å (4), are normal. In all cases, the coordination geometry about
gold is essentially linear, and the smallest C-Au-P angle (in
one independent molecule of 2) is 174.01(15)°. No intermo-
lecular gold-gold interactions are observed in any of the
structures.
Azide complex 1 was identified crystallographically among
the products from (unoptimized) reactions targeting cycload-
dition products 4 and 5. In these reactions, the gold starting
materials had been the acetylides. Nonhydrolyzable azides fail
to react with gold(I) alkynyls under identical conditions. Also,
internal alkynes do not react with 1. These observations might
suggest the intermediacy of 1 in the cycloaddition reactions
documented here and elsewhere.37-39 However, we cannot
dismiss the possibility of gold(I) alkynyl intermediacy. All gold-
(I) cycloaddition products so far encountered are air- and water-
stable.40,41 Collectively these experiments suggest an essential
stability of the carbon-gold bond that bodes favorably for
materials and medicinal applications.14,42,43
Results and Discussion
Reaction of a toluene slurry of 1 with phenylacetylene cleanly
affords the phenyltriazolate complex 2 in 78% isolated yield at
room temperature. Similarly, reaction of 1 with (p-fluorophenyl)-
acetylene yields the corresponding adduct 3 in 74% isolated
yield. In a variant of this reaction, triazolato complexes can be
generated from gold(I) alkynyls. Hence, (triphenylphosphine)-
gold(I) phenylacetylide (6) reacts with trimethylsilyl azide at
room temperature in the presence of methanol, affording 2 in
71% isolated yield. Neither starting material nor side products
are evident by 31P or 1H NMR after 48 h. Similarly, reaction of
the (p-fluorophenyl)acetylide complex 7 with trimethylsilyl azide
(37) Ziolo, R. F.; Thich, J. A.; Dori, Z. Inorg. Chem. 1972, 11, 626-
631.
(38) Wehlan, M.; Thiel, R.; Fuchs, J.; Beck, W.; Fehlhammer, W. P. J.
Organomet. Chem. 2000, 613, 159-169.
(39) Beck, W.; Burger, K.; Fehlhammer, W. P. Chem. Ber. 1971, 104,
1816-1825.
(40) Mohr, F.; Cerrada, E.; Laguna, M. Organometallics 2006, 25, 644-
(34) Joralemon, M. J.; O’Reilley, R. K.; Hawker, C. J. Wooley, K. L. J.
Am. Chem. Soc. 2005, 127, 16892-16899.
648.
(41) Sladek, A.; Hofreiter, S.; Paul, M.; Schmidbaur, H. J. Organomet.
Chem. 1995, 501, 47-51.
(42) Tiekink, E. R. T. Gold Bull. 2003, 36, 117-124.
(43) Shaw, C. F., III. In Gold: Progress in Chemistry, Biotechnology,
and Technology; Schmidbaur, H., Ed.; Wiley: New York, 1999; pp 259-
308.
(35) Diaz, D. D.; Rajagopal, K.; Strable, E.; Schneider, J.; Finn, M. G.
J. Am. Chem. Soc. 2006, 128, 6056-6057.
(36) Malkoch, M.; Schleicher, K.; Drockenmuller, E.; Hawker, C. J.;
Russell, T. P.; Wu, P.; Fokin, V. V. Macromolecules 2005, 38, 3663-
3678.

Cycloaddition Reactions of Gold(I)
Organometallics, Vol. 26, No. 1, 2007 185
[(PPh3)Au(t-butyltriazole)]. In 3 mL of toluene was dissolved
8 (69 mg, 0.13 mmol), and to this was added a 0.5 mL toluene
solution of trimethylsilyl azide (22 mg, 0.18 mmol). This solution
was stirred for 5 min, and 0.5 mL of methanol was added. This
solution was stirred for 24 h, and 0.03 mL of tert-butylacetylene
was added. The resultant solution was stirred for an additional 48
h and concentrated in vacuo to ∼2 mL. Pentane was added to
complete precipitation of a white solid, and the suspension was
cooled to -20 °C to maximize precipitation. The solid was collected
and dried. Yield: 63 mg (85%). 1H NMR (DMSO-d6): δ 13.94 (s
br, 1H, NH), 7.56-7.63 (m br, 15H, CH), 1.40 (s, 9H, C(CH3)3).
31P NMR (DMSO-d6): δ 44.7 ppm. Anal. Calcd for C24H25-
AuN3P: C, 49.41; H, 4.32; N, 7.20. Found: C, 49.25; H, 4.12; N,
6.96.
The foregoing results demonstrate that robust gold-carbon
bonds form upon cycloaddition of (triphenylphosphine)gold(I)
azide to terminal alkynes. The reaction occurs with purified 1
or with 1 prepared in situ from gold(I) alkynyls and trimeth-
ylsilyl azide in methanol. All reactions reported here yield
carbon-bound cycloadducts. Studies of gold(I) cycloaddition
reactions of other dipolarophiles and of more extensively
functionalized alkynes are underway.
Experimental Section
The alkynylgold precursors were prepared according to a
published procedure44 or by the reaction of [(PPh3)AuCl] with
alkyne in methanol in the presence of sodium methoxide. All other
solvents and reagents were used as received. Microanalyses (C, H,
and N) were performed by Quantitative Technologies Inc. NMR
spectra (1H, 31P) were recorded on a Varian AS-400 spectrometer.
Mass spectrometry was performed at the Michigan State University
Mass Spectrometry facility.
[(PPh3)Au(4-tolyltriazole)]. To a 4 mL toluene solution of 9
(100 mg, 0.17 mmol) was added a 0.5 mL toluene solution of
trimethylsilyl azide (32 mg, 0.26 mmol). This was stirred for 15
min, and 0.5 mL of methanol was added. The colorless solution
was stirred for 72 h and concentrated to ∼2 mL in vacuo, and
pentane was added to complete precipitation of a white solid, which
List of Compounds: [(PPh3)Au(N3)] (1); [(PPh3)Au-
(phenyltriazole)] (2); [(PPh3)Au((4-fluorophenyl)triazole)] (3); [(PPh3)-
Au(tert-butyltriazole)] (4); [(PPh3)Au(4-tolyltriazole)] (5); [(PPh3)-
Au(phenylacetylide)] (6); [(PPh3)Au((4-fluorophenyl)acetylide)] (7);
[(PPh3)Au(tert-butylacetylide)] (8); [(PPh3)Au(4-tolylacetylide)] (9).
Synthesis of [(PPh3)Au(N3)] (1). This was prepared differently
than the published procedure.45 In 8 mL of toluene was suspended
[(PPh3)AuCl] (167 mg, 0.34 mmol), and to this suspension was
added 1.05 equiv of [Tl(acac)] (108 mg, 0.35 mmol) with rapid
formation of a white solid. After 4 h, the suspension was filtered
through Celite, and to the filtrate was added a 1 mL toluene solution
of trimethylsilyl azide (58 mg, 0.48 mmol); the solution became
turbid. To this suspension was added 1 mL of methanol. The
reaction mixture was stirred for 20 h to produce a suspension that
was filtered through Celite, and the filtrate was concentrated to
∼3 mL in vacuo. Pentane was added to precipitate a white solid.
Yield: 134 mg (79%). MS (FAB+): m/z 502.0743 (MH+). Anal.
Calcd for C18H15AuN3P: C, 43.13; H, 3.02. Found: C, 43.13; H,
2.80. The IR spectral data matched those of an authentic sample.46
Synthesis of [(PPh3)Au(phenyltriazole)]. To a 4 mL toluene
solution of 6 (63 mg, 0.11 mmol) was added a 0.5 mL toluene
solution of trimethylsilyl azide (26 mg, 0.21 mmol). The reaction
mixture was stirred for 5 min, and 0.5 mL of methanol was added.
The solution was stirred for 48 h and was then concentrated in
vacuo to ∼2 mL. Pentane was added to precipitate a white solid.
1
was collected and dried. Yield: 97 mg (90%). H NMR (DMSO-
d6): δ 14.28 (s br, 1H, NH), 8.09 (d, 2H, CH), 7.56-7.68 (m,
15H, CH), 7.14 (d, 2H, CH), 2.28 (s, 3H, CH3) ppm. 31P NMR
(DMSO-d6): δ 44.5 ppm. Anal. Calcd for C27H23AuN3P: C, 52.52;
H, 3.75; N, 6.81. Found: C, 52.42; H, 3.48; N, 6.71.
Synthesis of 2 from [(PPh3)Au(N3)]. In 3 mL of toluene was
suspended [(PPh3)Au(N3)] (35 mg, 0.070 mmol), and to this
suspension was added a 1 mL toluene solution of phenylacetylene
(10 mg, 0.098 mmol). The resultant suspension was stirred under
argon for 48 h and filtered. The filtrate was concentrated in vacuo
to ∼0.5 mL, and pentane was added to precipitate a white solid,
1
which was collected and dried. The H and 31P NMR spectra of
this material in DMSO-d6 matched the spectra for 2. MS (FAB+):
m/z 604.1217 (MH+).
Synthesis of 3 from [(PPh3)Au(N3)]. In 4 mL of toluene was
suspended [(PPh3)Au(N3)] (61 mg, 0.12 mmol), and to this
suspension was added a 1 mL toluene solution of (4-fluorophenyl)-
acetylene (21 mg, 0.17 mmol). The resultant suspension was stirred
under argon for 48 h and concentrated in vacuo to half its original
volume. Pentane was added to complete precipitation of a white
solid, which was collected and dried. The 1H and 31P NMR spectra
of this material in DMSO-d6 matched the spectra for 3. MS
(FAB+): m/z 621.1117 (MH+).
X-ray Structure Determination. Compound 2 was crystallized
by diffusion of pentane into a saturated THF/toluene solution.
Compounds 3-5 were crystallized by diffusion of pentane into
saturated THF solutions. Single-crystal X-ray data for compounds
2-5 were collected on a Bruker AXS SMART APEX CCD
diffractometer using monochromatic Mo KR radiation with the
ω-scan technique. The unit cell was determined using SMART and
SAINT+.47 The crystals of 3 undergo a phase change between about
-20 and -30 °C, associated with a breakup of the crystals; data
for 3 were therefore collected at 260 K (-13.5 °C). The data
collections of 2, 4, and 5 were conducted at 100 K (-173.5 °C).
All structures were solved by direct methods and refined by full-
matrix least squares against F2 with all reflections using SHELX-
TL.48 Refinement of extinction coefficients was found to be
insignificant. All non-hydrogen atoms were refined anisotropically.
Compound 2 exhibits two independent gold complexes as well as
very large voids within the structure filled with ill-defined THF
solvate molecules (715 Å3 per asymmetric unit or 13 vol %). Three
THF molecules per asymmetric unit had been identified in the
1
Yield: 48 mg (71%). H NMR (DMSO-d6): δ 14.34 (s br, 1H,
NH), 8.22 (d, 2H, CH), 7.52-7.63 (m, 15H, CH), 7.35 (t, 2H, CH),
7.22 (t, 1H, CH) ppm. 31P NMR (DMSO-d6): δ 44.5 ppm. Anal.
Calcd for C26H21AuN3P: C, 51.75; H, 3.51; N, 6.96. Found: C,
51.35; H, 3.41, N, 6.80.
[(PPh3)Au(4-fluorophenyltriazole)]. To a 4 mL toluene solution
of 7 (79 mg, 0.14 mmol) was added a 0.5 mL toluene solution of
trimethylsilyl azide (32 mg, 0.26 mmol). This was stirred for 5
min, and 0.5 mL of methanol was added. The colorless solution
was stirred for 48 h and concentrated to approximately half the
original volume in vacuo, at which point it was a suspension.
Pentane was added to complete precipitation of a white solid, which
was collected, washed with pentane, and dried. Yield: 74 mg (87%).
1H NMR (DMSO-d6): δ 14.34 (s br, 1H, NH), 8.20 (dd, 2H, CH),
7.55-7.68 (m br, 15H, CH), 7.17 (t, 2H, CH). 31P NMR (DMSO-
d6): δ 44.5 ppm. Anal. Calcd for C26H20AuFN3P: C, 50.25; H,
3.24; N, 6.76. Found: C, 50.05; H, 3.03; N, 6.70.
(44) Vicente, J.; Chicote, M.; Abrisqueta, M. Organometallics 1997, 16,
5628-5636.
(47) (a) Bruker Advanced X-ray Solutions SMART for WNT/2000
(version 5.628); Bruker AXS Inc., Madison, WI, 1997-2002. (b) Bruker
Advanced X-ray Solutions SAINT (version 6.45), Bruker AXS Inc.,
Madison, WI 1997-2003.
(48) Bruker Advanced X-ray Solutions SHELXTL (version 6.10); Bruker
AXS Inc., Madison, WI, 2000.
(45) Beck, W.; Fehlhammer, W. P.; Po¨llman, P.; Scha¨chl, H. Chem. Ber.
1969, 102, 1976-1987.
(46) Beck, W.; Klapo¨tke, T. M.; Klu¨fers, P.; Kramer, G.; Riena¨cker, C.
M. Z. Anorg. Allg. Chem. 2001, 627, 1669-1674.

186 Organometallics, Vol. 26, No. 1, 2007
Table 1. Crystallographic Data for Gold Triazoles 2-5
Partyka et al.
2
3
4
5
formula
fw
C26H21AuN3P
603.39
C26H20AuFN3P
621.39
C27H23AuN3P
617.42
C24H25AuN3P
583.41
cryst syst
space group
a, Å
b, Å
c, Å
monoclinic
P21/c
tetragonal
P43
12.8693(3)
tetragonal
P43
13.7355(5)
tetragonal
P43
13.0753(8)
14.797(4)
22.554(7)
17.371(5)
109.840(5)
5453(3)
8
20.2649(14)
12.5315(9)
13.0705(12)
â, deg
cell vol, Å3
Z
2427.1(1)
4
1.700
2364.2(2)
4
1.735
2234.6(3)
4
1.734
D
calcd, Mg m-3
1.470
T, K
100(2)
5.469
2336
100(2)
6.152
1200
100(2)
6.310
1200
100(2)
6.670
1184
µ, mm-1
F(000)
cryst size, mm
0.055 × 0.121 × 0.543
1.46, 28.28
54 125
13 523
559
0.25 × 0.26 × 0.60
1.58, 28.28
25 118
5991
289
1.075
0.15 × 0.20 × 0.25
2.10, 28.28
22 982
5949
293
1.099
0.12 × 0.32 × 0.39
2.20, 30.43
17 060
4658
265
0.827
θmin, θmax, deg
no. of rflns collected
no. of indep rflns
no. of refined params
goodness of fit on F2 a
final R indicesb (I > 2σ(I))
R1
1.022
0.0421
0.1003
0.0225
0.0529
0.0342
0.0851
0.0382
0.0713
wR2
R indices (all data)
R1
wR2
0.0603
0.1070
0.0253
0.0541
0.0360
0.0866
0.0653
0.0757
2
2
a GOF ) [∑w(Fo2 - Fc )2/(n - p)]1/2; n ) number of reflections, p ) number of parameters refined. b R1 ) ∑(||Fo|| - |Fc||)/∑|Fo|; wR2 ) [∑w(Fo
-
2
4
Fc )2/∑wFo ]1/2
.
difference Fourier map, but a tentative refinement showed that the
molecules are ill-defined, partially disordered, and quite diffuse,
and no meaningful and stable refinement could be achieved. Thus,
the structure was refined with omission of the solvate molecules
and the diffuse sections of the unit cell were “squeezed out” using
the program Platon.49 The N-H hydrogen atoms of all three
structures were localized in the difference density Fourier map. The
N-H distance of 4 was refined and restrained to be 0.8 Å within
a standard deviation of 0.2; the other three N-H distances were
placed in calculated positions using an AFIX 43 command. All
other hydrogen atoms were placed in standard calculated positions,
and all hydrogen atoms were refined with an isotropic displacement
parameter 1.5 (CH3) or 1.2 (all others) times that of the adjacent
carbon or nitrogen atom.
Acknowledgment. We thank Case Western Reserve Uni-
versity and the donors of the Petroleum Research Fund,
administered by the American Chemical Society (Grant 42312-
G3 to T.G.G.), for support. The diffractometer was funded by
NSF Grant 0087210, by the Ohio Board of Regents Grant CAP-
491, and by Youngstown State University. We thank Mr. T. J.
Robilotto (CWRU) for experimental assistance. T.G.G. thanks
Professor J. D. Protasiewicz (CWRU) for stimulating discus-
sions.
Supporting Information Available: Figures showing the
structures of 2-4 and CIF files giving crystallographic data for
2-5. This material is available free of charge via the Internet at
http://pubs.acs.org.
Crystallographic data for 2-5 are given in Table 1.
(49) Spek, A. L. Platon for Windows; Delft, The Netherlands, 2003.
OM0607200