A novel type of alkynylgold(I) complex. Crystal and molecular structures of PPN[Au(Ar)(C=CH)] [Ar = C6F5, C6H2(NO2)3-2,4,6]

Article abstract of DOI:10.1021/om9910322

Complexes of the type PPN[Au(acac)(Ar)] [PPN = (Ph₃P)₂N, acac = acetylacetonate], obtained in solution from Tl(acac) and the corresponding PPN[Au-(Ar)Cl] derivatives after removal of TlCl, react in situ with ethyne to give a new type of ethynylgold(I) complex,

Full text of DOI:10.1021/om9910322

Organometallics 2000, 19, 2629-2632
2629
A Novel Typ e of Alk yn ylgold (I) Com p lex. Cr ysta l a n d
Molecu la r Str u ctu r es of P P N[Au (Ar )(CtCH)] [Ar ) C6F 5,
C6H2(NO2)3-2,4,6]
J ose´ Vicente,*,† Mar´ıa-Teresa Chicote,* and Mar´ıa-Dolores Abrisqueta
Grupo de Quı´mica Organometa´lica,‡ Departamento de Quı´mica Inorga´nica, Universidad de
Murcia, Aptdo. 4021, Murcia, 30071 Spain
Peter G. J ones*,§
Institut fu¨r Anorganische und Analytische Chemie, Technische Universita¨t Braunschweig,
Postfach 3329, 38023 Braunschweig, Germany
Received December 27, 1999
Summary: Complexes of the type PPN[Au(acac)(Ar)]
[PPN ) (Ph3P)2N, acac ) acetylacetonate], obtained in
solution from Tl(acac) and the corresponding PPN[Au-
(Ar)Cl] derivatives after removal of TlCl, react in situ
with ethyne to give a new type of ethynylgold(I) complex,
PPN[Au(Ar)(CtCH)] [Ar ) C6F5 (1), C6H4NO2-2 (2),
C6H2(NO2)3-2,4,6 (3)]. The crystal structures of 1 and 3
have been determined.
(L ) tertiary phosphine, L-L ) diphosphine).1d,4b,9
A
limited number of alkynylgold(I) complexes with isocya-
nide,1a,b,e,2,5g amine,5g,6a,10 carbene,5g or ylide ligands11
have also been reported, as have polymeric compounds
[Au2C2]n,12 [RCtCAu]n,6a or [AuCtCR′CtCAu]n.1a In
most cases, R or R′ is an aryl group, but a few examples
have R ) Me, Et,6b,13 CF3,1e,6b,f But,5g,6a,9e,11 Me3Si,5g
R′′CHX (X ) OH, Cl, Br),5g,14 CO2Me,6g,13 or MeOCH2.15
Despite the great number of reported alkynylgold(I)
complexes, the ethynyl derivatives are very scarce.6g,16
In this paper, we report new ethynylgold(I) complexes
[Au(Ar)(CtCH)]- (Ar ) C6F5, C6H4NO2-2, C6H2(NO2)3-
2,4,6) representing the first mixed arylalkynylgold
complexes. We also describe the first crystal structures
of ethynylgold complexes.
In tr od u ction
The preference of gold(I) for linear dicoordination,
together with the linearity of the CtC bond in alkynyl
ligands, makes alkynylgold(I) complexes attractive can-
didates for the design of linear-chain metal-containing
polymers with extended electronic conjugation along the
backbone.1 The rapidly growing interest in alkynylgold-
(I) complexes is associated with the expectation that
these electronically flexible rigid-rod polymers might
exhibit interesting properties either difficult or impos-
sible to achieve with conventional organic polymers.
Among the many alkynylgold(I) complexes described,
some show liquid crystalline properties2 or nonlinear-
optical behavior.3 In addition, some alkynylgold(I) de-
rivatives belong to a new class of luminophores with
interesting photophysical and photochemical proper-
ties.4
Exp er im en ta l Section
IR spectroscopy, elemental analyses, conductance measure-
ments in acetone solution, melting point determinations, and
NMR spectroscopy were carried out as described elsewhere.16c
Complexes PPN[Au(Ar)Cl] (Ar ) C6F5,17 C6H4NO2-2,18 and
C6H2(NO2)3-2,4,619 were prepared following the methods re-
ported in the literature. The NMR spectra were recorded in
(5) (a) Nast, R. Angew. Chem. 1965, 77, 352. (b) Abu-Salah, O. M.;
Al-Ohaly, A. R. Inorg. Chim. Acta 1983, 77, L159. (c) Abu-Salah, O.
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Anorg. Allg. Chem. 1964, 330, 311. (e) Perevalova, E. G.; Smyslova,
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497. (g) Vicente, J .; Chicote, M. T.; Abrisqueta, M. D.; J ones, P. G.
Organometallics 1997, 16, 5628.
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R. J .; Davidson, M. F. J . Chem. Soc., Dalton Trans. 1986, 411. (c)
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Chem., Int. Ed. Engl. 1997, 36, 370.
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Tiekink, E. R. T. J . Organomet. Chem. 1988, 344, C49. (b) Mu¨ller, T.
E.; Mingos, D. M. P.; Williams, D. J . J . Chem. Soc., Chem. Commun.
1994, 1787. (c) Hong, X.; Cheung, K. K.; Guo, C. X.; Che, C. M. J . Chem.
Soc., Dalton Trans. 1994, 1867. (d) Cross, R. J .; Davidson, M. F.;
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J .; Yufit, D. S. Chem. Commun. 1997, 219. Whittall, I. R.; Humphrey,
M. G.; Houbrechts, S.; Maes, J .; Persoons, A.; Schmid, S.; Hockless,
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Although a few of the reported alkynylgold(I) com-
plexes are anionic or cationic,5 most of them are neutral
and the majority correspond to the types [Au(CtCR)-
(L)],4a,5f,g,6 [(AuL)2(µ-CtC)]5g,7 [(AuL)2(µ-CtC-R-Ct
C)],1d [(AuL)3(µ-R{CtC}3)],8 or [{Au(CtCR)}2(µ-L-L)]
† E-mail: jvs@fcu.um.es.
‡ WWW: http://www.scc.um.es/gi/gqo/.
§ E-mail: jones@xray36.anchem.nat.tu-bs.de.
(1) (a) Irwin, M. J .; J ia, G. C.; Payne, N. C.; Puddephatt, R. J .
Organometallics 1996, 15, 51. (b) J ia, G. C.; Puddephatt, R. J .; Vittal,
J . J .; Payne, N. C. Organometallics 1993, 12, 263. (c) Irwin, M. J .;
Vittal, J . J .; Puddephatt, R. J . Organometallics 1997, 16, 3541. (d) J ia,
G. C.; Puddephatt, R. J .; Scott, J . D.; Vittal, J . J . Organometallics 1993,
12, 3565. (e) J ia, G. C.; Payne, N. C.; Vittal, J . J .; Puddephatt, R. J .
Organometallics 1993, 12, 4771.
(2) Alejos, P.; Coco, S.; Espinet, P. New J . Chem. 1995, 19, 799.
(3) Whittall, I. R.; McDonagh, A. M.; Humphrey, M. G.; Samoc, M.
Adv. Organomet. Chem. 1999, 43, 349.
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Dalton Trans. 1996, 3155. (b) Yam, V. W. W.; Choi, S. W. K. J . Chem.
Soc., Dalton Trans. 1996, 4227.
10.1021/om9910322 CCC: $19.00 © 2000 American Chemical Society
Publication on Web 05/17/2000

2630 Organometallics, Vol. 19, No. 13, 2000
Notes
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
CDCl3 at room temperature. Chemical shifts are referenced
to TMS [1H, 13C{1H}], H3PO4 [31P{1H}], or CFCl3 (19F). DEPT
experiments allowed us to assign the resonances from the
carbon nuclei attached to the gold atom. Some spectroscopic
data of the PPN cation, which are not listed below, are as
follows: NMR (δ), 1H, 7.4-7.7 (m, 30H); 13C{1H}, 127 (m, Cipso),
129.5 (m, Cortho), 132 (m, Cmeta), 134 (m, Cpara) ppm; 31P{1H},
20.9 (s) ppm; IR spectra, 1580 (m), 1320-1220 (s, br), 545 (s),
for 1 a n d 3
1
3
empirical formula
fw
cryst syst
space group
unit cell dimens
C47H37AuF5NOP2 C44H33AuN4O6P2
985.68
monoclinic
P21/c
a ) 9.9604(10) Å
b ) 15.3873(14) Å b ) 13.114(3) Å
c ) 26.682(3) Å
R ) 90°
â ) 92.738(8)°
γ ) 90°
972.65
triclinic
P1h
a ) 10.440(2) Å
525 (s), and 490 (s) cm-1
.
c ) 15.172(3) Å
R ) 80.508(12)°
â ) 80.789(14)°
γ ) 75.243(14)°
1965.9(7) Å3, 2
1.643 Mg/m3
3.88 mm-1
yellow tablet
0.25 × 0.15 ×
0.06 mm3
Syn th eses of P P N[Au (Ar )(CtCH)] [Ar ) C6F 5 (1),
C6H4NO2-2 (2), C6H2(NO2)3-2,4,6 (3)]. Tl(acac) (0.2-0.9 mmol)
was added to a solution of PPN[Au(Ar)Cl] (0.15-0.67 mmol)
in CH2Cl2 (20 mL) (1) or in acetone (20 mL) (2, 3), and the
resulting mixture was stirred for 40 min. The resulting
suspension was filtered through Celite, C2H2 was bubbled
through the solution for 30 min (1) or 2 h (2, 3) and it was
then filtered through anhydrous MgSO4. The filtrate was
concentrated to ca. 1 mL, and Et2O (20 mL) was added to
precipitate 1 as a white solid, and 2 or 3 as yellow solids.
1: yield, 80%. Mp: 148 °C. Anal. Calcd for C44H31AuF5NP2:
C, 56.97; H, 3.39; N, 1.51. Found: C, 56.48; H, 3.79; N, 1.42.
ΛM: 100 Ω-1 cm2 mol-1. NMR (300 MHz, δ): 1H, 1.59 (s,
tCH, 1H); 13C{1H}, 65.77 (s, tCH), 88.22 (s, AuCt); 19F,
-164.90 (m, 2F, m-F), -163.64 (m, 1F, p-F), -114.99 (m,
2F, o-F). Mass spectrum (FAB, negative ion mode): m/z
(% abundance) 389 (M-, 15.1), 532 ([Au(C6F5)2]-, 100), 752
volume, Z
density (calcd)
abs coeff
cryst habit
cryst size
4112.3(7) Å3, 4
1.592 Mg/m3
3.72 mm-1
colorless prism
0.45 × 0.35 ×
0.30 mm3
index ranges
0 e h e 12
-18 e k e 4
-31 e l e 31
9551
7225 [R(int) )
0.024]
-12 e h e 12
-14 e k e 15
-17 e l e 18
9128
6910 [R(int) )
0.058]
no. of reflns collected
no. of ind reflns
min. and max. transmn
0.71 and 0.86
0.76 and 0.92
481/514
0.84
0.063
0.038
no. of restraints/params 457/520
goodness-of-fit on F2
wR2 (all data)
R1 [I > 2σ(I)]
largest diff peak and
hole
0.89
([Au2(C6F5)2C2]2-
ν(CtC), 1970 (m); ν(C6F5), 1498, 948, 788.
,
16.9). IR (cm-1): ν(tC-H), 3268 (w);
0.060
0.031
1.13 and
0.99 and
2: yield, 88%. Mp: 168 °C. Anal. Calcd for
C44H35-
-0.44 e Å-3
-0.70 e Å-3
AuN2O2P2: C, 59.87; H, 4.00; N, 3.17. Found: C, 59.61; H, 3.94;
N, 3.07. ΛM: 106 Ω-1 cm2 mol-1. NMR (200 MHz, δ): 1H, 1.52
(s, tCH, 1H), 6.91 (m, C6H4, 1H), 7.20 (m, C6H4, 1H), 7.42-
7.68 (m, PPN + C6H4, 31H), 7.77 (m, C6H4, 1H); 13C{1H}, 89.11
(s, tCH), 122.56 (s, C6H4), 123.17 (s, C6H4), 127.10 (s, AuCCH),
130.56 (s, C6H4), 142.94 (s, C6H4), 159.14 (s, CAu), 169.11 (s,
CNO2). IR (cm-1): ν(tC-H), 3284 (w); ν(CtC), 1968 (w);
gas stream (-100 °C) of a Siemens P4 diffractometer. Data
were registered to 2θmax 50° in ω-scan mode using Mo KR
radiation (λ ) 0.71073 Å). Absorption corrections were applied
on the basis of ψ-scans. Structures were solved by the heavy-
atom method and refined anisotropically on F2 (program
SHELXL-93, G. M. Sheldrick, University of Go¨ttingen). Hy-
drogen atoms were included with a riding model (exception:
the acetylenic H of 1 was located and refined freely). A system
of restraints (to local ring symmetry and light atom displace-
ment parameters) was employed to ensure refinement stabil-
ity.
νasym(NO2), 1504 (m).
3: yield, 56%. Mp: 170 °C (dec). Anal. Calcd for C44H33
-
AuN4O6P2: C, 54.33; H, 3.42; N, 5.76. Found: C, 54.26; H, 3.38;
N, 5.56. ΛM: 88 Ω-1 cm2 mol-1. NMR (200 MHz): 1H, 1.57 (s,
tCH, 1H), 8.66 (s, C6H2, 2H); 13C{1H}, 90.05 (s, tCH), 120.17
(s, C6H2), 121.51 (s, AuCt), 143.96 (s, C6H2), 160.46 (s, C6H2).
IR (cm-1): ν(tC-H), 3259 (w); ν(CtC), 1962 (w); νasim(NO2),
1530 (s), 1514 (s).
Resu lts a n d Discu ssion
X-r a y Cr ysta llogr a p h ic An a lysis of 1 a n d 3. Crystal data
and refinement details are presented in Table 1. Crystals were
mounted on glass fibers in inert oil and transferred to the cold
Syn th eses of Com p lexes. The aryl(ethynyl)aurate-
(I) complexes PPN[Au(Ar)(CtCH)] [Ar ) C6F5 (1), C6H4-
NO2-2 (2), C6H2(NO2)3-2,4,6 (3)] were obtained by
treating PPN[Au(Ar)Cl] (Ar ) C6F5, C6H4NO2-2, C6H2-
(NO2)3-2,4,6)20 with Tl(acac), removing TlCl by filtration,
and bubbling ethyne through the resulting solution
(Scheme 1). The reactions proceeded equally well in
dichloromethane or acetone, and complexes 1 and 2
were obtained in high yield (80% 1 and 88% 2), while
the yield for 3 is only moderate due to its lower stability.
It is reasonable to assume that these reactions occur
through the formation of the corresponding acetyl-
acetonato complexes A, which would react in situ with
an excess of ethyne to give complexes 1-3. These are
new examples of the utility of acetylacetonatogold(I)
compounds in the synthesis of a wide variety of gold(I)
complexes, by deprotonating organic substrates contain-
ing even weakly acidic hydrogen atoms.21 The aryl-
(acetylacetonato)gold(I) intermediates seem to be stable
in solution, but all attempts to isolate them led to
(9) (a) Li, D.; Hong, X.; Che, C. M.; Lo, W. C.; Peng, S. M. J . Chem.
Soc., Dalton Trans. 1993, 2929. (b) Yam, V. W. W.; Choi, S. W. K.;
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S. W. K.; Cheung, K. K. J . Chem. Soc., Dalton Trans. 1996, 3411. (d)
Tzeng, B. C.; Lo, W. C.; Che, C. M.; Peng, S. M. Chem. Commun. 1996,
181. (e) Payne, N. C.; Ramachandran, R.; Puddephatt, R. J . Can. J .
Chem. 1995, 73, 6.
(10) Yau, J .; Mingos, D. M. P. J . Chem. Soc., Dalton Trans. 1997,
1103.
(11) Aguirre, C. J .; Gimeno, M. C.; Laguna, A.; Laguna, M.; Lo´pez
de Luzuriaga, J . M.; Puente, F. Inorg. Chim. Acta 1993, 208, 31.
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Chem. 1984, 37, 1163.
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Organomet. Chem. 1988, 344, 119.
(15) Carriedo, G. A.; Riera, V.; Solans, X.; Solans, J . Acta Crystallogr.
C 1988, 44, 978.
(16) (a) Nast, R.; Schneller, P.; Hengefeld, A. J . Organomet. Chem.
1981, 214, 273. (b) Vicente, J .; Chicote, M. T.; Abrisqueta, M. D.; J ones,
P. G. Organometallics 1997, 16, 5628. (c) Vicente, J .; Chicote, M. T.;
Lagunas, M. C.; J ones, P. G. J . Chem. Soc., Dalton Trans. 1991, 2579.
(17) Uso´n, R.; Laguna, A.; Vicente, J . J . Organomet. Chem. 1977,
131, 471.
(18) Vicente, J .; Arcas, A.; Chicote, M. T. J . Organomet. Chem. 1983,
252, 257.
(19) Vicente, J .; Arcas, A.; J ones, P. G.; Lautner, J . J . Chem. Soc.,
Dalton Trans. 1990, 451.
(20) Vicente, J .; Chicote, M. T.; Gonza´lez-Herrero, P.; Gru¨nwald, C.
Organometallics 1997, 16, 3381.
(21) Vicente, J .; Chicote, M. T. Coord. Chem. Rev. 1999, 193-195,
1143.

Notes
Organometallics, Vol. 19, No. 13, 2000 2631
Sch em e 1
F igu r e 1. Thermal ellipsoid plot of the anion of 1 (50%
probability levels) with the labeling scheme. Selected bond
lengths (Å) and angles (deg): Au-C(7) 1.984(6), Au-C(1)
2.049(5), C(7)-C(8) 1.175(8), C(7)-Au-C(1) 176.9(2), C(8)-
C(7)-Au 174.6(5).
F igu r e 2. Thermal ellipsoid plot of the anion of 3 (50%
probability levels) with the labeling scheme. Selected bond
lengths (Å) and angles (deg): Au-C(1) 2.0148(56), Au-
C(3) 2.0392(54), C(1)-C(2) 1.1469(73), N(1)-O(1) 1.2118-
(54), N(1)-O(2) 1.2166(54), N(2)-O(4) 1.2180(59), N(2)-
O(3) 1.2212(61), N(3)-O(6) 1.2123(55), N(3)-O(5) 1.2156(53),
C(1)-Au-C(3) 175.5(2), C(2)-C(1)-Au 175.6(5).
correspond to the starting pentafluorophenyl complexes.
Recrystallization of this compound (or mixture), whereby
some decomposition to give colloidal gold is observed,
leads always to the same result. We also attempted the
synthesis of the dinuclear complex using diethyl- or
triethylamine as the base, but in both cases complex
mixtures formed, which could not be separated. We have
previously described16b the syntheses of neutral mono-
nuclear [Au(CtCR)(L)] (R ) SiMe3, But, L ) PPh3,
PCy3, CNBut) or dinuclear [(AuL)2{µ-CtC(CH2)5CtC}]
(L ) PPh3, CNBut) alkynyl complexes by reacting [AuCl-
(L)] and the corresponding alkyne or dialkyne in the
presence of a base. On that occasion we used NHEt2 or
NEt3 interchangeably, except in the case of L ) But-
NC, for which NHEt2 must be excluded to avoid forma-
tion of the carbene complex [Au(CtCR){C(NHBut)-
NEt2}] by attack of the secondary amine NHEt2 on the
isocyanide ligand.
Str u ctu r e of Com p lexes. As far as we are aware,
complexes 1 and 3 are the first ethynylgold complexes
characterized by X-ray diffraction methods. Both crystal
structures display the dicoordinate gold atom in a quasi
linear environment with C-Au-C angles of 176.9(2)°
(1) and 175.5(2)° (3). The Au-CtC bond angle [1, 176.9-
(2)°; 3, 175.5(2)°] is also slightly bent, as is the case in
most alkynylgold(I) complexes; values as low as 172-
(1)°22 or 173.5(6)° 23 are not infrequent. The Au-Cethynyl
extensive decomposition to give colloidal gold.
The reaction (in acetone, 48 h) between equimolar
amounts of PPN[Au(C6F5)(CtCH)] (1) and PPN[Au-
(C6F5)Cl] and a small excess of KOH leads, after
concentration to dryness, extraction with dichloro-
methane, filtration of the extract, concentration of the
resulting solution, and addition of n-pentane, to a white
precipitate. Its 13C{1H} NMR spectrum [δ 88.20 (s, AuC)
ppm], elemental analyses [found: C, 56.60; H, 3.28; N,
1.05; calcd for C86H60Au2F10N2P4: C, 56.47; H, 3.31; N,
1.53], molar conductivity in acetone [ΛM, 196 Ω-1cm2
mol-1 (5.6 × 10-4 mol L-1)], and mass spectrum ((FAB,
negative ion mode): m/z (% abundance) 752 (M2-, 18.8),
389 ([C6HAuF5]- 20.9), 531 ([C12AuF10]-, 100)) are in
agreement with its formulation as a dinuclear complex,
PPN2[{Au(C6F5)}2(µ-CtC)]. Thus we assumed that the
[Au(CtC)(C6F5)]2- ligand resulting from deprotonation
of the terminal alkyne complex 1 by the base KOH
displaced the chloro ligand present in PPN[Au(C6F5)-
Cl] to give the dinuclear complex with concomitant
formation of insoluble KCl. However, the 19F{1H} NMR
spectrum indicates the presence of two different types
of C6F5 groups in an approximately 2:1 ratio [the more
abundant one gives resonances to -113.96 (m, o-F),
-164.20 (t, p-F), and -165.01(m, m-F) ppm and the
other one at -115.37 (m, o-F), -163.15 (t, p-F), and
-164.49 (m, m-F) ppm]. None of these resonances
(22) Ko¨hler, K.; Silverio, S. J .; Hyla-Kryspin, I.; Gleiter, R.; Zsolnai,
L.; Driess, A.; Huttner, G.; Lang, H. Organometallics 1997, 16, 4970.

2632 Organometallics, Vol. 19, No. 13, 2000
Notes
[1.984(6) (1), 2.015(6) (3) Å] and the CtC [1.175(8)
(1), 1.147(7) (3) Å] bond distances are slightly
longer and shorter, respectively, with respect to the
mean value found for a series of alkynylgold com-
plexes1d,7a,9a,e,13,15,16b,23,24 (mean Au-Calkynyl, 1.97 Å,
mean CtCAu, 1.199 Å). The lengthening of the Au-
Cethynyl bond distance could be due to the greater trans
influence of the aryl ligand than the usual ligands in
other alkynylgold complexes. The strengthening of the
CtC bond in ethynyl with respect to other alkynyl
ligands had been previously observed in complexes of
other elements.25
[2.039(5) Å] is similar or slightly longer, respectively,
compared to those found in [Au(SbPh3)4][Au{C6H2-
(NO2)3-2,4,6}2] [2.041(13) and 2.015(12) Å] or [Au{C6H2-
(NO2)3-2,4,6}(dmphen)] (dmphen ) 2,9-dimethyl-1,10-
phenanthroline) [2.000(3) Å]swhich are the only two
other trinitrophenylgold(I) complexes available for
comparison19sas expected for carbon or nitrogen donor
ligands trans to the Au-Caryl bond, respectively. In
complex 3, the presence of the three electron-withdraw-
ing nitro groups causes severe distortion of the aromatic
angles, mainly affecting the angle centered at the carbon
atom bonded to the metal [C8-C3-C-4, 111.0(5)°]. The
narrowing of the endocyclic angle at the ipso carbon [in
the range 108.9(11)19-113.7(10)° 30a] is a common fea-
ture for trinitrophenyl complexes and has been ac-
counted for in the same terms as mentioned for 1.19,30
The rotation of the nitro groups with respect to the
mean plane of the phenyl ring observed in 3 [23.9° and
54.6° for the nitro groups ortho to the gold atom and
only 7.3° for that in the para position] is similar to that
found in other nitro-33 and trinitrophenyl complexes.30,32
NMR a n d IR Sp ectr a . In complexes 1-3 the reso-
nances due to the ethynyl proton [at δ 1.59 (1), 1.52 (2),
and 1.57 (3) ppm] is in the range found for other
ethynylgold complexes (δ 1.37-1.81 ppm),16b highfield
shifted in all cases with respect to that of ethyne (δ 1.80
ppm). This suggests that the arylgold fragment attached
to the -CtCH moiety is less electronegative than the
proton. The 13C{1H} NMR spectra of complexes 1-3
show the ethynyl carbon nuclei in the ranges δ 65.77-
90.05 (tCH) and δ 88.20-127.10 (AuCt) ppm. Other
anionic ethynylgold(I) complexes show the analogous
resonances in the ranges δ 82-87 and δ 103-127
ppm.16b
In complex 1, the C-C [1.350(6)-1.387(6) Å] and C-F
[1.342(5)-1.372(5) Å] bond distances within the pen-
tafluorophenyl ring are normal.20,26 The Au-Caryl bond
distance [2.049(5) Å] is similar to those found in other
pentafluorophenylgold(I) complexes with methanide,27
carbene,28 or aryl26c ligands but longer than in com-
plexes with sulfur20 or nitrogen26a donor ligands, con-
sistent with the stronger trans influence of carbon donor
ligands. The bond angles in the pentafluorophenyl ring
are in the range 112.7(5)-125.3(5)°, the smallest angle
being centered at the ipso carbon. This distortion has
been previously observed in other aryl complexes,
including pentafluorophenylgold derivatives;26a,27,29 its
magnitude depends on the nature of the ring substitu-
ents, and it has been accounted for19,30 in terms of Bent’s
isovalent hybridization concept.31
In complex 3, the C-C [1.382(7)-1.403(7) Å], C-N
[1.474(7)-1.492(7) Å], and N-O [1.212(6)-1.221(6) Å]
bond distances within the aryl ring are in the range
found in those few trinitrophenyl complexes structurally
characterized.19,30,32 The Au-Caryl bond distance in 3
The IR spectra of complexes 1-3 show one νCtC
stretching band [at 1970 m (1), 1968 w (2), 1962 w (3)
cm-1] slightly shifted to low energy with respect to that
of ethyne [at 1974 cm-1 (Raman)].34 This effect suggests
that the arylgold moieties exert +I or +M effects, which
would be enhanced by the anionic character of the
complexes. This has been observed in other anionic
ethynylgold complexes.16b The spectra show also the
corresponding νCH stretching mode as a weak band [at
3268 (1), 3284 (2), 3259 (3) cm-1] in the range previously
reported for ethynyl complexes of gold or other ele-
ments.16b,25 The IR spectra show also strong or medium
absorptions characteristic of the pentafluorophenyl35
(1: 1498, 948, 788 cm-1) or nitrophenyl18 (2: 1504; 3:
1530, 1514 cm-1) ligands.
(23) Whittall, I. R.; Humphrey, M. G.; Houbrechts, S.; Persoons, A.;
Hockless, D. C. R. Organometallics 1996, 15, 5738.
(24) Mu¨ller, T. E.; Choi, S. W. K.; Mingos, D. M. P.; Murphy, D.;
Williams, D. J .; Yam, V. W. W. J . Organomet. Chem. 1994, 484, 209.
Shieh, S. J .; Hong, X.; Peng, S. M.; Che, C. M. J . Chem. Soc., Dalton
Trans. 1994, 3067. Bruce, M. I.; Duffy, D. N. Aust. J . Chem. 1986, 39,
1697.
(25) Manna, J .; J ohn, K. D.; Hopkins, M. D. Avd. Organomet. Chem.
1995, 38, 79.
(26) (a) Bordoni, S.; Busetto, L.; Cassani, M. C.; Albano, V. G.;
Sabatino, P. Inorg. Chim. Acta 1994, 222, 267. (b) J ones, P. G. Z.
Naturforsch. 1982, 37B, 937. (c) Uso´n, R.; Laguna, A.; Vicente, J .;
Garc´ıa, J .; J ones, P. G.; Sheldrick, G. M. J . Chem. Soc., Dalton Trans.
1981, 65.
(27) Uso´n, R.; Laguna, A.; Laguna, M.; La´zaro, I.; J ones, P. G.
Organometallics 1987, 6, 2326.
(28) Byers, P. K.; Carr, N.; Stone, F. G. A. J . Chem. Soc., Dalton
Trans. 1990, 3701.
(29) J ones, P. G. J . Organomet. Chem. 1988, 345, 405.
(30) (a) Vicente, J .; Arcas, A.; Borrachero, M. V.; Mol´ıns, E.;
Miravitlles, C. J . Organomet. Chem. 1992, 441, 487. (b) Vicente, J .;
Arcas, A.; Borrachero, M. V.; de Goicoechea, M. L.; Lanfranchi, M.;
Tiripicchio, A. Inorg. Chim. Acta 1990, 177, 247.
Ack n ow led gm en t . We thank DGES (PB97-1047)
and the Fonds der Chemischen Industrie for financial
support. M.-D.A. thanks CajaMurcia for a Posdoctoral
Grant.
(31) Bent, H. A. Chem. Rev. 1961, 61, 275.
(32) Vicente, J .; Arcas, A.; Borrachero, M. V.; Molı´ns, E.; Miravitlles,
C. J . Organomet. Chem. 1989, 359, 127.
(33) Vicente, J .; Chicote, M. T.; Martin, J .; J ones, P. G.; Fittschen,
C.; Sheldrick, G. M. J . Chem. Soc., Dalton Trans. 1986, 2215. Vicente,
J .; Chicote, M. T.; Martin, J .; Artigao, M.; Solans, X.; Font-Altaba, M.;
Aguilo´, M. J . Chem. Soc., Dalton Trans. 1988, 141.
(34) Nakamoto, K. Infrared and Raman Spectra of Inorganic and
Coordination Compounds, 4th ed.; J ohn Wiley and Sons: New York,
1986; p 390. Iwashita, Y.; Tamura, F.; Nakamura, A. Inorg. Chem.
1969, 8, 1179.
Su p p or tin g In for m a tion Ava ila ble: Atomic positional
parameters for the freely refined atoms, bond lengths and
interbond angles, atomic displacement parameters, and hy-
drogen atom parameters. This material is available free of
charge via the Internet at http://pubs.acs.org.
(35) Long, D. A.; Steele, D. Spectrochim. Acta 1961, 19, 1955.
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