Synthesis and characterization of new silver complexes of alkynes. Single-crystal structures of (1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)-(diphenylacetylene)silver and tetrakis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)bis(4-octyne)tetrasilver

Article abstract of DOI:10.1021/om960190f

Novel silver alkyne complexes of the empirical formula [(hfac)Ag]_nL, where hfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato and n = 1 for L = diphenylacetylene (1) and bis(trimethylsilyl)acetylene (2) and n = 2 for L = 2-butyne (3), 2-hexyne (4), 3-hexyne (5), and 4-octyne (6), were prepared from reactions of Ag₂O with hfacH in the presence of the corresponding alkynes. X-ray single-crystal diffraction analyses reveal that compound 1 is a mononuclear silver complex with a coordination number of 3 and compound 6 is a tetranuclear silver species in which each silver atom is four-coordinate.

Full text of DOI:10.1021/om960190f

2660
Organometallics 1996, 15, 2660-2663
Syn th esis a n d Ch a r a cter iza tion of New Silver Com p lexes
of Alk yn es. Sin gle-Cr ysta l Str u ctu r es of
(1,1,1,5,5,5-Hexa flu or o-2,4-p en ta n ed ion a to)-
(d ip h en yla cetylen e)silver a n d Tetr a k is(1,1,1,5,5,5-
h exa flu or o-2,4-p en ta n ed ion a to)bis(4-octyn e)tetr a silver
Kai-Ming Chi* and Chia-Tien Lin
Department of Chemistry, National Chung Cheng University, Ming-Hsiung,
Chia-Yi, Taiwan, ROC
Shie-Ming Peng and Gene-Hsiang Lee
Department of Chemistry, National Taiwan University, Taipei, Taiwan, ROC
Received March 12, 1996X
Summary: Novel silver alkyne complexes of the empirical
formula [(hfac)Ag]nL, where hfac ) 1,1,1,5,5,5-hexafluoro-
2,4-pentanedionato and n ) 1 for L ) diphenylacetylene
(1) and bis(trimethylsilyl)acetylene (2) and n ) 2 for L
) 2-butyne (3), 2-hexyne (4), 3-hexyne (5), and 4-octyne
(6), were prepared from reactions of Ag2O with hfacH
in the presence of the corresponding alkynes. X-ray
single-crystal diffraction analyses reveal that compound
1 is a mononuclear silver complex with a coordination
number of 3 and compound 6 is a tetranuclear silver
species in which each silver atom is four-coordinate.
π-coordinated alkyne complexes are [Ag(TBC)2]+, where
TBC ) 1,2:5,6:9,10-tribenzocyclododeca-1,5,9-triene-
3,7,11-triyne,10 and the polymeric species [(CF3SO3)-
AgL]n, where L ) 1,6-cyclodecadiyne, 1,7-cyclododec-
adiyne, and 1,8-cyclotetradecadiyne.11 Thus, it is
valuable to investigate the preparation and structural
properties of (â-diketonato)silver alkyne compounds and
their potential as CVD precursors. Here we report the
synthesis and characterization of several (hfac)Ag alkyne
complexes (hfac ) 1,1,1,5,5,5-hexafluoro-2,4-pentanedi-
onato) and single-crystal structures of two of these
compounds.
In tr od u ction
Exp er im en ta l Section
It has been shown that (â-diketonato)copper(I) com-
plexes of alkynes are suitable for chemical vapor deposi-
tion (CVD) of pure copper films.1 The synthesis and
structural characterization of the analogous compounds
of silver have not been reported, although they have
been mentioned in the patent literature.2 As a matter
of fact, relatively few examples of silver complexes of
alkynes have been reported.3 Most of these compounds
contain silver centers asymmetrically π-coordinated
with acetylenic CtC bonds which σ-bond to other
metals.4-9 The only two examples of symmetrically
Gen er a l P r oced u r es a n d Sta r tin g Ma ter ia ls. All op-
erations were performed under an atmosphere of nitrogen
purified by passage through columns of activated BASF
catalyst and molecular sieves and using standard Schlenk
techniques12 in conjunction with a double-manifold vacuum
line. All hydrocarbon and ethereal solvents were dried and
distilled from sodium benzophenone ketyl at atmospheric
pressure before use. Silver(I) oxide, 1,1,1,5,5,5-hexafluoro-2,4-
pentanedione, diphenylacetylene, bis(trimethylsilyl)acetylene,
2-butyne, 2-hexyne, 3-hexyne, and 4-octyne (Aldrich Chemical
Co.) were used without further purification. Elemental analy-
ses were carried out at the National Science Council Southern
Instrument Center (Department of Chemistry, National Cheng
Kung University). NMR data were recorded on a Varian
Gemini-200 NMR spectrometer by using the protio impurities
* To whom correspondence should be addressed.
X Abstract published in Advance ACS Abstracts, May 1, 1996.
(1) (a) J ain, A.; Chi, K.-M.; Kodas, T. T.; Hampden-Smith, M. J .;
Farr, J . D.; Paffett, M. Chem. Mater. 1991, 3, 995. (b) Baum, T. H.;
Larson, C. E. Chem. Mater. 1992, 4, 365. (c) Kodas, T. T.; Hampden-
Smith, M. J . The Chemistry of Metal CVD; VCH: Weinheim, Germany,
1994; Chapter 5.
(2) Baum, T. H.; Larson, C. E.; Reynolds, S. K. US Patent 5,096,737,
1992.
(3) Lang, H.; Kohler, K.; Blau, S. Coord. Chem. Rev. 1995, 143, 113
and references cited therein.
(4) Corfield, P. W. R.; Shearer, H. M. M. Acta Crystallogr. 1966, 20,
502.
(5) (a) Abu-Salah, O. M.; Bruce, M. I.; Churchill, M. R.; DeBoer, B.
G. J . Chem. Soc., Chem. Commun. 1974, 688. (b) Churchill, M. R.;
DeBoer, B. G. Inorg. Chem. 1975, 14, 2630. (c) Abu-Salah, O. M.;
Bruce, M. I. Aust. J . Chem. 1977, 30, 2639.
(6) (a) Abu-Salah, O.; Knobler, C. B. J . Organomet. Chem. 1986,
302, C10. (b) Mazhar-Ul-Haque; Horne, W.; Abu-Salah, O. M. J .
Crystallogr. Spectrosc. Res. 1992, 22, 421.
(7) (a) Espinet, P.; Fornies, J .; Martinez, F.; Tomas, M.; Lalinde,
E.; Moreno, M. T.; Ruiz, A.; Welch, A. J . J . Chem. Soc., Dalton Trans.
1990, 791. (b) Espinet, P.; Fornies, J .; Martinez, F.; Sotes, M.; Lalinde,
E.; Moreno, M. T.; Ruiz, A.; Welch, A. J . J . Organomet. Chem. 1991,
403, 253. (c) Fornies, J .; Gomez-Saso, M. A.; Martinez, F.; Lalinde,
E.; Moreno, M. T.; Welch, A. J . New. J . Chem. 1992, 16, 483. (d)
Fornies, J .; Lalinde, E.; Martinez, F.; Moreno, M. T.; Welch, A. J . J .
Organomet. Chem. 1993, 455, 271.
1
of deuterated solvents as references for the H NMR and the
13C signals of the solvents as references for 13C NMR spec-
troscopy. 19F NMR spectra were externally referenced to
CFCl3. Infrared data were recorded on a Perkin-Elmer Model
16 PC FTIR spectrophotometer. Melting points were mea-
sured in sealed capillaries on a Thomas-Hoover Unimelt
instrument without calibration.
Syn th esis a n d Ch a r a cter iza tion of th e (h fa c)Ag Com -
p lexes of Alk yn es. a . (h fa c)Ag(P h CtCP h ) (1). A solution
of diphenylacetylene (0.77 g, 4.32 mmol) in 20 mL of Et2O was
transferred to a 250-mL Schlenk flask containing a slurry
(8) J in, X.-L.; Zhou, G.-D.; Wu, N.-Z.; Tang, Y.-Q.; Huang, H.-C. Acta
Chim. Sin. 1990, 48, 232.
(9) Lang, H.; Herres, M.; Zsolnai, L. Organometallics 1993, 12, 5008.
(10) Ferrara, J . D.; Djebli, A.; Tessier-Youngs, C.; Youngs, W. J . J .
Am. Chem. Soc. 1988, 110, 647.
(11) Gleiter, R.; Karcher, M.; Kratz, D.; Ziegler, M. L.; Nuber, B.
Chem. Ber. 1990, 123, 1461.
(12) Shriver, D. F.; Drezdon, M. A. The Manipulation of Air-Sensitive
Compounds, 2nd ed.; Wiley: New York, 1986.
S0276-7333(96)00190-2 CCC: $12.00 © 1996 American Chemical Society

Notes
Organometallics, Vol. 15, No. 11, 1996 2661
Ta ble 1. Su m m a r y of Cr ysta llogr a p h ic Da ta for
Com p ou n d s 1 a n d 6
solution of Ag2O (0.50 g, 2.16 mmol) in Et2O (30 mL). After
the solution was stirred for 30 min and cooled to -30 °C, a
solution of hfacH (0.61, 4.32 mmol) in Et2O (30 mL) was added
to the reaction flask dropwise. The solution mixture was
stirred for 4 h and slowly warmed to room temperature. After
filtration and removal of the volatile components in vacuo (0.1
Torr), a pale yellow powder was obtained. Recrystallization
of the compound from hexane (10 mL) at 0 °C afforded 1.66 g
(78% yield) of analytically pure, white product.
1
6
emp formula
fw
C19H11O2AgF6
493.15
C36H32O8Ag4F24
1480.06
0.08 × 0.30 × 0.60
monoclinic; P21/c
11.475(3)
cryst size (mm3)
space group
a (Å)
0.20 × 0.40 × 0.45
triclinic; P1h
12.335(3)
12.387(3)
14.509(3)
68.945(17)
87.751(20)
66.324(20)
1880.3(7)
4
b (Å)
c (Å)
26.924(6)
16.549(5)
Anal. Calcd for C19H11O2F6Ag: C, 46.28; H, 2.25. Found:
C, 46.06; H, 2.27. NMR data (C6D6, 18 °C): 1H δ 7.49 (m, 4H,
H on diphenylacetylene), 7.02 (m, 6H, H on diphenylacetylene),
6.12 (s, 1H, CH on hfac) ppm; 13C{1H} δ 177.9 (q, J F-C ) 31.7
Hz, CF3CO on hfac), 132.8 (s), 129.4 (s), 129.2 (s), 124.3 (s)
(phenyl C’s on diphenylacetylene), 119.3 (q, J F-C ) 287.3 Hz,
CF3 on hfac), 90.6 (s, PhCtCPh), 88.1 (s, CH on hfac) ppm;
19F{1H} δ -76.5 (s) ppm. IR data (KBr disk): νCtC 1963 (w),
νCO 1659 (s), 1558 (m), 1524 (s), 1498 cm-1. Mp: 113 °C dec.
R (deg)
â (deg)
105.58(3)
γ (deg)
V (Å3)
4924.9(23)
4
1.996
0.7107
298.00
2849
Z
d(calcd) (g/cm3)
λ (Å)
T (K)
1.742
0.7107
298.00
968
F(000)
2θ range (deg)
15.52-25.60
16.66-30.52
b. (h fa c)Ag(Me3SiCtCSiMe3) (2). White, crystalline
compound 2 was prepared in 82% yield with a procedure
analogous to that for the synthesis of compound 1.
scan type
θ/2θ
θ/2θ
scan speed (deg/min) 2.06-8.24
scan width (deg)
2.06-8.24
2(0.60 + 0.35 tan θ) 2(0.70 + 0.35 tan θ)
45.0
11.266
Anal. Calcd for
C13H19O2F6Si2Ag: C, 32.17; H, 3.95.
2θmax
45.0
16.848
Found: C, 32.15; H, 3.95. NMR data (C6D6, 18 °C): 1H δ 6.17
(s, 1H, CH on hfac), 0.12 (s, 18H, (CH3)3SiCtCSi(CH3)3) ppm;
13C{1H} δ 178.5 (q, J F-C ) 32.2 Hz, CF3CO on hfac), 119.2 (q,
J F-C ) 287.3 Hz, CF3 on hfac), 108.7 (s, (CH3)3SiCtCSi(CH3)3),
88.4 (s, CH on hfac), 0.6 (s, (CH3)3SiCtCSi(CH3)3) ppm;
19F{1H} δ -76.5 (s) ppm. IR data (KBr disk): νCtC 2009 (w),
µ (cm-1
)
transmissn
0.864; 1.000
-12 < h < 13
0 < k < 13
-14 < l < 15
0.037; 0.040
2.00
0.749; 1.000
-12 < h < 11
0 < k < 28
0 < l < 17
0.047; 0.049
1.11
index ranges
a
RF; Rw
goodness of fitb
weights scheme
refinement program
no. of atoms
νCO 1655 (s), 1540 (s), 1498 (s), 1420 (m) cm-1
dec;
.
Mp: 67 °C
sublima-
1/σ2(Fo)
NRCVAX
78
1/σ2(Fo)
NRCVAX
104
tion temperature 40 °C/0.1 Torr.
no. of params refined 506
650
0.0298
c. [(h fa c)Ag]2(MeCtCMe) (3). Pale yellow, crystalline
compound 3 was prepared in 78% yield following a procedure
similar to that for the synthesis of compound 1.
largest ∆/σ
0.0243
a
RF ) ∑(Fo - Fc)/∑Fo. Rw ) (∑[w(Fo - Fc)2]/∑(wFo2))1/2
.
Goodness of fit ) [∑[w(Fo - Fc)2]/[(no. of reflections) - (no. of
parameters)]]1/2
b
Anal. Calcd for C14H8O4F12Ag2: C, 24.59; H, 1.18. Found:
C, 24.38; H, 1.19. NMR data (C6D6, 18 °C): 1H δ 6.13 (s, 2H,
CH on hfac), 1.40 (s, 6H, H3CCtCCH3) ppm; 13C{1H} δ 178.6
(q, J F-C ) 31.9 Hz, CF3CO on hfac), 119.6 (q, J F-C ) 292.2 Hz,
CF3 on hfac), 89.3 (s, CH on hfac), 75.3 (s, H3CCtCCH3), 5.1
(s, H3CCtCCH3) ppm; 19F{1H} δ -76.8 (s) ppm. IR data (KBr
disk): νCtC 2166 (w), νCO 1673 (s), 1609 (s), 1530 (s) cm-1. Mp:
73 °C dec.
d . [(h fa c)Ag]2(MeCtCnP r ) (4). Pale yellow, crystalline
compound 4 was prepared in 71% yield by using a procedure
analogous to that for the synthesis of compound 1.
.
f. [(h fa c)Ag]2(nP r CtCnP r ) (6). White, crystalline com-
pound 6 was prepared in 70% yield by using a procedure
analogous to that of synthesis of compound 1.
Anal. Calcd for C18H16O4F12Ag2: C, 29.21; H, 2.18. Found:
C, 28.86; H, 2.08. NMR data (C6D6, 18 °C): 1H δ 6.15 (s, 2H,
methine CH on hfac), 1.86 (t, 4H, J H-H ) 7.04 Hz, CH2CH2-
CH3 on 4-octyne), 1.27 (m, 4H, CH2CH2CH3 on 4-octyne), 0.76
(t, 6H, J H-H ) 7.27 Hz, CH3 on 4-octyne) ppm; 13C{1H} δ 177.4
(q, J F-C ) 32.0 Hz, CF3CO on hfac), 118.7 (q, J F-C ) 287.6 Hz,
CF3 on hfac), 87.3 (s, CH on hfac), 80.0 (s, -CtC- on 4-octyne),
23.1 (s, CH2CH2CH3 on 4-octyne), 21.7 (s, CH2CH2CH3 on
4-octyne), 13.3 (s, CH3 on 4-octyne) ppm; 19F{1H} δ -76.4 (s)
ppm. IR data (KBr disk): νCtC 2176 (w), νCO 1682 (s), 1659
(s), 1563 (s) 1513 (s) cm-1. Mp: 67 °C dec.
Anal. Calcd for C16H12O4F12Ag2: C, 26.99; H, 1.70. Found:
C, 26.53; H, 1.94. NMR data (C6D6, 18 °C): 1H δ 6.10 (s, 2H,
methine CH on hfac), 1.80 (m, 4H, CH2CH2CH3 on 2-hexyne),
1.42 (s, 6H, CH3 on 2-hexyne), 1.27 (m, 4H, CH2CH2CH3 on
2-hexyne), 0.74 (m, 6H, J H-H ) 7.33 Hz, CH2CH2CH3 on
2-hexyne) ppm; 13C{1H} δ 178.3 (q, J F-C ) 33.0 Hz, CF3CO on
hfac), 119.5 (q, J F-C ) 288.0 Hz, CF3 on hfac), 88.5 (s, CH on
hfac), 79.7 (s, acetylenic C on 2-hexyne), 76.0 (s, acetylenic C
on 2-hexyne), 24.0 (s, CH2CH2CH3 on 2-hexyne), 22.7 (s,
CH2CH2CH3 on 2-hexyne), 14.1 (s, CH2CH2CH3 on 2-hexyne),
5.1 (s, CH3 on 2-hexyne) ppm; 19F{1H} δ -76.4 (s) ppm. IR
data (KBr disk): νCtC 2175 (w), νCO 1658 (s), 1650 (s), 1565
(s), 1530 (s), 1493 (s) cm-1. Mp: 66 °C dec.
X-r a y Sin gle-Cr ysta l Str u ctu r e Deter m in a tion . Two
examples of the title compounds were characterized structur-
ally in the solid state by single-crystal X-ray diffraction. All
diffraction data were collected on an Enraf-Nonius CAD-4
diffractometer with monochromated Mo KR radiation (λ )
0.709 30 Å) using the θ/2θ scan mode. Crystal, collection, and
refinement data are summarized in Table 1.
e. [(h fa c)Ag]2(EtCtCEt) (5). Pale yellow, crystalline
compound 5 was prepared in 71% yield by using a procedure
analogous to that of synthesis of compound 1.
a . (h fa c)Ag(P h CtCP h ) (1). White cubic crystals of
compound 1 were grown by crystallization from a hexane-
diethyl ether mixed solution at -20 °C, and a single crystal of
dimensions 0.20 × 0.40 × 0.45 mm3 was selected for X-ray
analysis. Cell parameters were determined from the fit of 25
reflections (15.52 < 2θ < 25.60°). All data were corrected for
Lorentz and polarization effects and for effects of absorption.
A total of 4900 reflections was collected, but only 3441 unique
reflections with I > 2σ(I) were used for structure solution and
refinement. The structure was solved by the heavy-atom
method and refined by full-matrix least squares based on F
values. All non-hydrogen atoms were refined with anisotropic
Anal. Calcd for C16H12O4F12Ag2: C, 26.99; H, 1.70. Found:
C, 27.25; H, 2.00. NMR data (C6D6, 18 °C): 1H δ 6.13 (s, 2H,
methine CH on hfac), 1.69 (q, 4H, J H-H ) 7.50 Hz, CH2 on
3-hexyne), 0.87 (t, 6H, J H-H ) 7.43 Hz, CH3 on 3-hexyne) ppm;
13C{1H} δ 178.6 (q, J F-C ) 31.9 Hz, CF3CO on hfac), 119.5 (q,
J F-C ) 288.0 Hz, CF3 on hfac), 88.8 (s, CH on hfac), 81.5 (s,
-CtC- on 3-hexyne), 15.6 (s, CH2 on 3-hexyne), 14.8 (s, CH3
on 3-hexyne) ppm; 19F{1H} δ -76.7 (s) ppm. IR data (KBr
disk): νCtC 2147 (w) νCO 1655 (s), 1567 (s), 1540 (s), 1513 (s)
cm-1. Mp: 55 °C dec.
thermal parameters. The final agreement factors are RF
)

2662 Organometallics, Vol. 15, No. 11, 1996
Notes
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
0.037 and Rw ) 0.040 with w ) 1/σ2(Fo). The atomic scattering
factors were taken from ref 13.
(d eg) for Com p ou n d 1
b. [(h fa c)Ag]2(nP r CtCnP r ) (6). White needlelike crystals
of compound 6 were grown by crystallization from hexane
solution at -20 °C, and a single crystal of dimensions 0.08 ×
0.30 × 0.60 mm3 was selected for X-ray analysis. Cell
parameters were determined from the fit of 25 reflections
(16.66 < 2θ < 30.52°). All data were corrected for Lorentz
and polarization effects and for effects of absorption. A total
of 6414 reflections was collected, but only 3397 unique reflec-
tions with I > 2σ(I) were used for structure solution and
refinement. The structure was solved by the heavy-atom
method and refined by full-matrix least squares based on F
values. All non-hydrogen atoms were refined with anisotropic
Bond Lengths
Ag(1a)-O(1a)
Ag(1a)-O(2a)
Ag(1a)-C(1a)
Ag(1a)-C(2a)
O(1a)-C(16a)
O(2a)-C(18a)
C(1a)-C(2a)
2.234(4)
2.228(4)
2.261(6)
2.263(6)
1.238(7)
1.243(7)
1.208(8)
1.393(8)
1.380(8)
Ag(b)-O(1b)
Ag(1b)-O(2b)
Ag(1b)-C(1b)
Ag(1b)-C(2b)
O(1b)-C(16b)
O(1b)-C(18b)
C(1b)-C(2b)
C(16b)-C(17b)
C(17b)-C(18b)
2.229(4)
2.231(4)
2.272(5)
2.278(5)
1.258(7)
1.231(7)
1.201(8)
1.372(8)
1.389(8)
C(16a)-C(17a)
C(17a)-C(18a)
Bond Angles
O(1a)-Ag(1a)-O(2a) 84.22(14) O(1b)-Ag(1b)-O(2b) 83.97(14)
O(1a)-Ag(1a)-C(1a) 121.37(18) O(1b)-Ag(1b)-C(1b) 119.80(17)
O(1a)-Ag(1a)-C(2a) 152.32(18) O(1b)-Ag(1b)-C(2b) 150.42(17)
O(2a)-Ag(1a)-C(1a) 154.36(18) O(2b)-Ag(1b)-C(1b) 156.18(17)
O(2a)-Ag(1a)-C(2a) 123.46(18) O(2b)-Ag(1b)-C(2b) 125.61(17)
thermal parameters. The final agreement factors are RF
)
0.047 and Rw ) 0.049 with w ) 1/σ2(Fo). The atomic scattering
factors were taken from ref 13.
C(1a)-Ag(1a)-C(2a)
Ag(1a)-C(1a)-C(2a)
Ag(1a)-C(1a)-C(3a) 119.7(4)
Ag(1a)-C(2a)-C(1a) 74.4(4)
Ag(1a)-C(2a)-C(9a) 119.7(4)
C(2a)-C(1a)-C(3a)
C(1a)-C(2a)-C(9a)
30.98(21) C(1b)-Ag(1b)-C(2b)
74.6(4) Ag(1b)-C(1b)-C(2b)
30.62(20)
75.0(4)
Resu lts a n d Discu ssion
Ag(1b)-C(1b)-C(3b) 117.8(4)
Ag(1b)-C(2b)-C(1b) 74.4(4)
Ag(1b)-C(2b)-C(9b) 117.2(4)
The title compounds were prepared from reactions of
Ag2O with hfacH in the presence of the corresponding
alkyne according to eq 1. These reactions were carried
167.5(6)
165.9(6)
C(2b)-C(1b)-C(3b)
C(1b)-C(2b)-C(9b)
167.2(6)
168.4(6)
Ag2O + 2hfacH + excess RCtCR′ f
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Com p ou n d 6
+ H O (1)
[(hfac)Ag]n(RCtCR′)
1-6
2
Bond Lengths
Ag(1)-O(1)
Ag(1)-O(3)
Ag(1)-O(5)
Ag(2)-O(3)
Ag(2)-O(4)
Ag(2)-O(5)
Ag(2)-O(6)
Ag(3)-O(1)
Ag(3)-O(2)
Ag(3)-O(7)
Ag(3)-O(8)
Ag(4)-O(2)
Ag(4)-O(4)
Ag(4)-O(8)
2.383(9)
2.418(9)
2.506(9)
2.500(9)
2.424(8)
2.419(9)
2.360(8)
2.421(8)
2.534(9)
2.391(9)
2.389(8)
2.417(9)
2.387(9)
2.499(8)
Ag(1)-C(4)
Ag(1)-C(5)
C(4)-C(5)
2.347(15)
2.332(15)
1.12(3)
2.305(15)
2.328(20)
1.13(3)
1.240(15)
1.254(15)
1.248(15)
1.257(16)
1.239(15)
1.216(15)
1.237(16)
1.257(15)
n ) 1: R ) R′ ) Ph (1); R ) R′ ) Me3Si (2)
Ag(4)-C(12)
Ag(4)-C(13)
C(12)-C(13)
O(1)-C(18)
O(2)-C(20)
O(3)-C(23)
O(4)-C(25)
O(5)-C(28)
O(6)-C(30)
O(7)-C(33)
O(8)-C(35)
n ) 2: R ) R′ ) Me (3); R ) Me, R′ ) nPr (4);
R ) R′ ) Et (5); R ) R′ ) nPr (6)
out in Et2O solutions, and products were isolated by
extraction with hexane and removal of volatile species
in vacuo. Two kinds of compounds were obtained. The
1
integrated H NMR spectra of these compounds show
that they have the empirical formula [(hfac)Ag]nL, in
which n ) 1 for L ) diphenylacetylene (1) and bis-
(trimethylsilyl)acetylene (2) and n ) 2 for L ) 2-butyne
(3), 2-hexyne (4), 3-hexyne (5), and 4-octyne (6). El-
emental analyses of these compounds are consistent
with the formula. They are thermally stable at ambient
temperature and moderately sensitive to air, moisture,
and light. Examination of the volatility of these com-
pounds has been carried out by sublimation under
reduced pressure (about 100 mTorr). Compound 2 can
be sublimed without decomposition at 40 °C; the others
decomposed before sublimination occurred. The 13C
NMR resonances of the acetylenic carbons for com-
pounds 1-6 are slightly upfield (0.1-5.9 ppm) relative
to these for the free alkynes. This feature implies weak
interaction between the CtC triple bond and silver
center in the title compounds.
The molecular structures of compounds 1 and 6 were
determined in the solid state by single-crystal X-ray
diffraction analyses. The crystal, collection, and refine-
ment data are summarized in Table 1. Selected bond
lengths and bond angles are given in Tables 2 and 3 for
compounds 1 and 6, respectively. Two independent
molecules of compound 1 exist in the unit cell. An
ORTEP plot of one molecule is shown in Figure 1. This
compound is mononuclear in the solid state, and the
coordination geometry about the silver center is ap-
proximately trigonal-planar and resembles those of (â-
Bond Angles
O(1)-Ag(1)-O(3)
O(1)-Ag(1)-O(5)
O(3)-Ag(1)-O(5)
C(4)-Ag(1)-C(5)
Ag(1)-C(4)-C(5)
Ag(1)-C(5)-C(4)
C(3)-C(4)-C(5)
C(4)-C(5)-C(6)
O(3)-Ag(2)-O(4)
O(3)-Ag(2)-O(5)
77.0(3)
81.5(3)
81.0(3)
27.8(6)
O(1)-Ag(3)-(2)
O(1)-Ag(3)-(7)
O(1)-Ag(3)-(8)
O(2)-Ag(3)-(7)
70.0(3)
130.6(3)
151.0(3)
147.6(3)
81.2(3)
76.6(3)
75.4(3)
81.4(3)
79.6(3)
28.1(8)
77.1(13)
74.8(13)
75.4(11) O(2)-Ag(3)-(8)
76.8(11) O(7)-Ag(3)-(8)
168.4(17) O(2)-Ag(4)-O(4)
166.8(19) O(2)-Ag(4)-O(8)
70.9(3)
81.1(3)
O(4)-Ag(4)-O(8)
C(12)-Ag(4)-C(13)
Ag(4)-C(12)-C(13)
Ag(4)-C(13)-C(12)
C(11)-C(12)-C(13) 169.0(20)
C(12)-C(13)-C(14) 166.3(22)
O(3)-Ag(2)-O(6) 146.3(3)
O(4)-Ag(2)-O(5) 151.4(3)
O(4)-Ag(2)-O(6) 131.6(3)
O(5)-Ag(2)-O(6)
75.8(3)
diketonato)copper alkyne complexes.14 The atoms O(1),
O(2), C(1), and C(2) are mutually coplanar, and the
silver atom lies slightly above the plane (0.011(3) Å and
0.017(3) Å for molecules a and b, respectively). The
Ag-O bond distances, the O-Ag-O bite angle, and
other bond lengths and angles within the hfac ligand
are similar to those observed for other examples of
(hfac)Ag complexes.15-17 The coordinated alkyne shows
(14) (a) Chi, K. M.; Shin, H.-K.; Hampden-Smith, M. J .; Kodas, T.
T.; Duesler, E. N. Inorg. Chem. 1991, 30, 4293. (b) Baum, T. H.;
Larson, C. E. Chem. Mater. 1992, 4, 365. (c) Lang, H.; Kohler, K.;
Buchner, M. Chem. Ber. 1995, 128, 525.
(15) Yuan, Z.; Dryden, N. H.; Vittal, J . J .; Puddephatt, R. J . Chem.
Mater. 1995, 7, 1696.
(13) International Tables for X-ray Crystallography; Kynoch Press:
Birmingham, U.K., 1974; Vol. IV.
(16) Yuan, Z.; Dryden, N. H.; Li, X.; Vittal, J . J .; Puddephatt, R. J .
J . Mater. Chem. 1995, 5, 303.

Notes
Organometallics, Vol. 15, No. 11, 1996 2663
F igu r e 2. ORTEP diagram of the molecular structure of
compound 6.
fashion. The CtC bond distances of alkynes are
unusually short and not accurate because of decomposi-
tion of the compound during the data collection. Bond
lengths between Ag and C of alkynes longer than those
in the molecule of compound 1 indicate the weaker
interaction between silver and alkyne in compound 6.
In summary, we prepared two kinds of new silver
complexes of alkynes. All compounds were character-
ized by analytical and spectroscopic methods. Struc-
tural properties of two compounds were determined by
single-crystal X-ray diffraction analysis. Among these
compounds, compound 2 is volatile and can be sublimed
at 40 °C under reduced pressure (about 100 mTorr).
Examination of the application of this species to chemi-
cal vapor deposition is in process.
F igu r e 1. ORTEP diagram of the molecular structure of
compound 1.
a C-C bond distance similar to that of free alkyne,
C-C-Ph deformation angles of 167°, and long Ag-C
bond distances (about 2.26 Å). These structural features
are in agreement with poor π-back-donation from silver
to the alkyne ligand.
Compound 6 is a tetranuclear species in the solid
state that is similar to the analogous complex of
norbornadiene [(hfac)Ag]4(nbd)2.17 An ORTEP diagram
showing the atomic labeling scheme of this compound
is presented in Figure 2. Four silver atoms lie on a
plane and are bound together with bridging hfac ligands.
There are two kinds of silver atoms in the molecule:
Ag(1) and Ag(4) are coordinated with CtC of alkyne and
three O atoms of different hfac ligands; Ag(2) and Ag(3)
are coordinated with four O atoms of two chelating hfac
ligands. Each silver center is four-coordinate with the
coordination geometry of a distorted tetrahedron. The
hfac ligands exhibit two types of coordination modes:
one bridges two Ag atoms (Ag(1), Ag(2) or Ag(3), Ag(4))
in a µ2 fashion and the other bridges three Ag atoms
(Ag(1), Ag(2), Ag(4) or Ag(1), Ag(3), Ag(4)) in a µ3
Ack n ow led gm en t. We thank the National Science
Council of the Republic of China (NSC Grant No. 83-
0208-M-194-003) and National Chung Cheng University
for financial support of this work.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data for compounds 1 and 6, including tables of crystal data,
atomic coordinates, bond distances bond angles, and aniso-
tropic thermal parameters (29 pages). Ordering information
is given on any current masthead page.
(17) Xu, C.; Corbitt, T. S.; Hampden-Smith, M. J .; Kodas, T. T.;
Duesler, E. N. J . Chem. Soc., Dalton Trans. 1994, 2841.
OM960190F