Phosphane-and phosphite-silver(I) phenolates: Synthesis, characterization and their use as CVD precursors

Article abstract of DOI:10.1016/j.ica.2010.05.049

The silver(I) salts [AgOR] (3a, R = C₉H₆N; 3b, R = C₆H₄-2-CHO, 3c, R = C₆H₄-2-Cl; 3d, R = C₆H₄-2-CN; 3e, R = C₆H₄-2-NO ₂) are accessible by the stoichiometric reaction of [AgNO ₃] (1) with HOR (2a, R = C₉H₆N; 2b, R = C ₆H₄-2-CHO; 2c, R = C₆H₄-2-Cl; 2d, R = C₆H₄-2-CN; 2e, R = C₆H₄-2-NO ₂) in presence of NEt₃. Treatment of 3a-3e with P ⁿBu₃ (4), P(OMe)₃ (5a) or P(OCH ₂CF₃)₃ (5b) in the ratios of 1:1 and 1:2, respectively, produced complexes [L_mAgOR] (L = PⁿBu ₃, m = 1: 6a, R = C₉H₆N; 6b, R = C ₆H₄-2-CHO; 6c, R = C₆H₄-2-Cl; 6d, R = C₆H₄-2-CN; 6e, R = C₆H₄-2-NO ₂. m = 2: 7a, R = C₉H₄; 7b, R = C ₆H₄-2-CHO; 7c, R = C₆H₄-2-Cl; 7d, R = C₆H₄-2-CN; 7e, R = C₆H₄-2-NO ₂. L = P(OMe)₃, m = 1: 8a, R = C₆H ₄-2-CHO; 8b, R = C₆H₄-2-NO₂. m = 2: 9, R = C₆H₄-2-NO₂. L = P(OCH₂CF ₃)₃, m = 1: 10, R = C₆H₄-2-NO ₂). Based on TGA, temperature-programmed and in situ molecular beam mass spectrometry metal-organic 7e was applied as CVD precursor in the deposition of silver onto glass substrates. The resulting silver films were characterized by XRD. The SEM image of a film grown from 7e at 350 °C showed a homogeneous surface with grain sizes of 40 nm. The molecular structures of 8b and 10 in the solid state were determined. They are isostructural and are cubane-like structured. Low-temperature ³¹P{¹H} NMR studies showed that the title complexes are dynamic in solution and exchange at room temperature their ligands.

Full text of DOI:10.1016/j.ica.2010.05.049

Inorganica Chimica Acta 365 (2011) 1–9
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Phosphane- and phosphite-silver(I) phenolates: Synthesis, characterization and
their use as CVD precursors
Alexander Jakob a, Heike Schmidt a, Bernhard Walfort a, Tobias Rüffer a, Thomas Haase b,
Katharina Kohse-Höinghaus b, Heinrich Lang a,
⇑
a Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Institut für Chemie, Lehrstuhl für Anorganische Chemie, Straße der Nationen 62, 09111 Chemnitz, Germany
b Universität Bielefeld, Physikalische Chemie I, Postfach 100131, 33501 Bielefeld, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
The silver(I) salts [AgOR] (3a, R = C9H6N; 3b, R = C6H4-2-CHO, 3c, R = C6H4-2-Cl; 3d, R = C6H4-2-C„N; 3e,
R = C6H4-2-NO2) are accessible by the stoichiometric reaction of [AgNO3] (1) with HOR (2a, R = C9H6N; 2b,
R = C6H4-2-CHO; 2c, R = C6H4-2-Cl; 2d, R = C6H4-2-C„N; 2e, R = C6H4-2-NO2) in presence of NEt3. Treat-
ment of 3a–3e with PnBu3 (4), P(OMe)3 (5a) or P(OCH2CF3)3 (5b) in the ratios of 1:1 and 1:2, respectively,
produced complexes [LmAgOR] (L = PnBu3, m = 1: 6a, R = C9H6N; 6b, R = C6H4-2-CHO; 6c, R = C6H4-2-Cl;
6d, R = C6H4-2-C„N; 6e, R = C6H4-2-NO2. m = 2: 7a, R = C9H4; 7b, R = C6H4-2-CHO; 7c, R = C6H4-2-Cl;
7d, R = C6H4-2-C„N; 7e, R = C6H4-2-NO2. L = P(OMe)3, m = 1: 8a, R = C6H4-2-CHO; 8b, R = C6H4-2-NO2.
m = 2: 9, R = C6H4-2-NO2. L = P(OCH2CF3)3, m = 1: 10, R = C6H4-2-NO2). Based on TGA, temperature-pro-
grammed and in situ molecular beam mass spectrometry metal–organic 7e was applied as CVD precursor
in the deposition of silver onto glass substrates. The resulting silver films were characterized by XRD. The
SEM image of a film grown from 7e at 350 °C showed a homogeneous surface with grain sizes of 40 nm.
The molecular structures of 8b and 10 in the solid state were determined. They are isostructural and are
cubane-like structured. Low-temperature 31P{1H} NMR studies showed that the title complexes are
dynamic in solution and exchange at room temperature their ligands.
Received 9 February 2010
Accepted 20 May 2010
Available online 16 September 2010
Keywords:
Phosphane
Phosphite
Silver
CVD
Mass spectrometry
Ó 2010 Published by Elsevier B.V.
1. Introduction
chemical vapor deposition method [10]. The films produced are of
poor quality and the respective precursors are solids.
The growth of coinage metal films is of great interest with re-
cent advances made in the deposition of copper, [1] silver, [2]
and gold [3] using the CVD (= Chemical Vapor Deposition) process.
Lately, silver becomes more valuable in the field of microelectron-
ics, due to its lowest resistivity and highest thermal conductivity of
all metals. [4] Further applications include, for example, the use of
This prompted us to prepare a series of novel phosphane and
phosphite silver(I) phenolates and to apply them as possible CVD
precursors for the deposition of silver on glass substrates. The ther-
mal stability of these metal–organic complexes and the potential
formation mechanism of silver-containing fragments in the gas-
phase by temperature-programmed and in situ molecular beam
mass spectrometry is reported as well.
silver as
a component of high-temperature superconducting
ceramics [5], as silver mirrors [6], or as bactericidal coatings [7].
One of the mayor problems in silver-CVD is the availability of suit-
able precursors which are stable, volatile, and economical in their
synthesis [8]. There have been several reports on the use of Lewis-
base silver(I) b-diketonates as suitable CVD precursors [2a,9], how-
ever, to date new silver complexes which can be efficiently used for
CVD deposition experiments are still not sufficiently available. In
addition, the gas-phase deposition mechanism of such species is
still not completely understood. Among thus, from the family of
silver(I) phenolates only triphenyl-phosphane silver(I) phenolate,
cresolate and trichlorophenolate have been reported by Molloy et
al. to grow silver films on glass substrates using an aerosol-assisted
2. Experimental
2.1. General information
All reactions were carried out under an atmosphere of purified
nitrogen (O2 traces: CuO catalyst, BASF AG, Ludwigshafen; H2O:
molecular sieve 4 Å, Aldrich Company) using standard Schlenk
techniques. Dichloromethane and acetonitrile were purified by
distillation from P2O5, diethyl ether and petroleum ether from so-
dium/benzophenone ketyl, and ethanol from sodium and diet-
hylphthalate. Infrared spectra were recorded with a Perkin Elmer
FT-IR spectrometer (Spectrum 1000) (KBr for solids and NaCl plates
for liquids). 1H NMR spectra were recorded with a Bruker Avance
250 spectrometer operating at 250.130 MHz in the Fourier
⇑
Corresponding author. Tel.: +49 (0)371 531 21210; fax: +49 (0)371 531 21219.
E-mail address: heinrich.lang@chemie.tu-chemnitz.de (H. Lang).
0020-1693/$ - see front matter Ó 2010 Published by Elsevier B.V.
doi:10.1016/j.ica.2010.05.049

2
A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
transform mode. 13C{1H} NMR spectra were recorded at
62.895 MHz. Chemical shifts are reported in d units (parts per mil-
lion) downfield from tetramethylsilane (d = 0.00 ppm) with the
solvent as the reference signal (1H NMR, CDCl3, d = 7.26; 13C{1H}
NMR, CDCl3, d = 77.55). 31P{1H} NMR spectra were recorded at
101.255 MHz in CDCl3 with P(OMe)3 as external standard (d =
139.0, rel. to H3PO4 (85%) with d = 0.00). Thermogravimetric stud-
ies were carried out with the Perkin Elmer System Pyris TGA 6 with
a constant heating rate of 8 K minÀ1 under N2 (20.0 dm3 hÀ1).
Microanalyses were performed by the Institute of Organic Chemis-
try, University of Heidelberg (Heraeus C, H ,N-Analyzer) and the
Institute of Organic Chemistry, Chemnitz Technical University
(Foss Heraeus Vario EL C, H, N-Analyzer). The melting (decomposi-
tion) points were determined with a Gallenkamp MFB 595 010 M
melting point apparatus. For in situ mass spectrometric experi-
ments, a molecular beam was extracted through a quartz nozzle
from the deposition zone of a CVD reactor, expanded and investi-
gated in a time-of-flight mass spectrometer. The precursor was
evaporated using a pulsed spray evaporation technique and trans-
ported to the deposition zone (heated quartz tube, length 100 mm)
at a pressure of 50 mbar. Argon was used as the carrier gas at a
flow rate of 100 sccm. The electron impact ionization took place
at a pressure of 10À6 mbar at the ionization energy of 30 eV [11].
The CVD experiments were performed in a vertical cold-wall reac-
tor with stagnation point flow geometry. The precursor was intro-
duced into the reactor using the pulsed spray evaporation
technique. Glass (square, diameter 25 mm) was used as substrate.
More details on the reactor setup can be found in reference [11].
work-up, 3c could be isolated as a colorless, temperature and light
sensitive solid which best should be stored at low temperature and
in the dark. Yield: 0.36 g (1.5 mmol, 26% based on 2c).
Anal. Calc. for C6H4AgClO (235.41): C, 30.61; H, 1.71. Found: C,
~
30.74; H, 1.73%. Mp: 73 °CÀ1(decomp.). IR (KBr, cmÀ1):
m (C@C)
~
m
1576, 1469,
(CO) 1309 cm
.
2.6. Synthesis of [AgOC6H4-2-C„N] (3d)
Complex 3d was synthesized as described for 3a (Section 2.3):
2-Cyanophenol (2d) (1.79 g, 17.7 mmol), [AgNO3] (1) (3.0 g,
17.7 mmol), and NEt3 (1.79 g, 17.7 mmol). The silver(I) salt 3d
could be isolated as a colorless, temperature and light sensitive so-
lid. Storage at low temperature and in the dark is recommended.
Yield: 3.54 g (15.7 mmol, 88% based on 2d).
Anal. Calc. for C7H4AgNO (225.98): C, 37.20; H, 1.78; N, 6.20.
Found: C, 37.16; H, 1.74; N, 6.29%. Mp: 118 °C (decomp.). IR (KBr,
À1
cmÀ1):
(C„N) 2209,
m
.
~
m
~
m
~
(C„C) 1596, 1539, (CO) 1274 cm
2.7. Synthesi of [AgOC6H4-2-NO2] (3e) [12b]
Metal–organic 3e was synthesized according to 3a (Section 2.3)
with following details: 2-nitrophenol (2e) (1.80 g, 17.8 mmol),
[AgNO3] (1) (3.02 g, 17.8 mmol), and NEt3 (1.80 g, 17.8 mmol).
After appropriate work-up, 3e could be isolated as an orange-red
solid. Yield: 3.09 g (12.6 mmol, 71% based on 2e).
~
~
Mp: 67 °C (decomp.). IR:
m
(C„C) 1610, 1538,
m
(NO) 1495,
~
1324,
m
(CO) 1243 cmÀ1
.
1H NMR (CD3CN): d 6.36 (dd, 1 H, H3,
3JHH = 7.6 Hz, JHH = 7.6 Hz), 6.78 (d, 1 H, H4, JHH = 9.0 Hz), 7.22
3
3
3
3
4
2.2. Reagents
(ddd, 1 H, H2, JHH = 8.8 Hz, JHH = 6.9 Hz, JHH = 1.9 Hz), 7.82 (dd,
1 H, H1, JHH = 8.4 Hz, JHH = 1.9 Hz). Please, notice that due to the
high thermal instability of 3e no satisfying elemental analysis
could be obtained. It is advised to store 3e low temperature to pre-
vent significant decomposition!
3
4
All reagents used in the synthesis of 3 and 6–10 were purchased
from commercial suppliers and were used as received.
2.3. Synthesis of [AgOC9H6N] (3a) [12a]
2.8. Synthesis of [nBu3PAgOC9H6N] (6a)
8-Hydroxychinoline (2a) (1.16 g, 8.0 mmol) was dissolved in
30 mL of ethanol and triethylamine (810 mg, 8.0 mmol) was added
in a single portion. This mixture was drop-wise added to [AgNO3]
(1) (1.36 g, 8.0 mmol) dissolved in 30 mL of ethanol and 3 mL of
acetonitrile, respectively, at 0 °C. After stirring the reaction mixture
for 2 h at this temperature, the precipitate was collected and was
thoroughly washed with 10 mL of ethanol and three times with
petroleum ether (20 mL). The yellow solid was dried in oil-pump
vacuum giving 1.64 g (6.5 mmol, 81% based on 2a) of the title com-
plex. Complex 3a is insoluble in common organic solvents.
nBu3P (4) (510 mg, 2.5 mmol) was added in a single portion to
3a (640 mg, 2.6 mmol, 2% excess based on 4) suspended in 40 mL
of diethyl ether at 25 °C. After stirring the reaction mixture for
2 h at this temperature it was filtered through a pad of Celite. Re-
moval of all volatiles in oil-pump vacuum produced a yellow solid.
Yield: 1.12 g (2.5 mmol, 98% based on 4).
Anal. Calc. for C21H33AgNOP (454.32): C, 55.51; H, 7.32; N, 3.08.
Found: C, 54.98; H, 7.29; N, 3.09%. Mp: 28 °C. IR (KBr, cmÀ1):
(CO), 1318 cmÀ1 1H NMR (CDCl3): d 0.93 (t, 9 H,
~
(C@C) 1592, m .
m
Anal. Calc. for C9H6AgNO (252.01): C, 42.89; H, 2.40; N, 2.40.
CH3, JHH = 7.0 Hz), 1.39–1.75 (m, 18 H, CH2CH2CH2CH3), 6.86 (dd,
Found: C, 43.29; H, 2.69, N, 2.81%. Mp: 297 °C (decomp.). IR (KBr,
1 H, H1, 3JHH = 7.0 Hz, 4JHH = 1.0 Hz), 7.03 (dd, 1 H, H3, 3JHH = 8.0 Hz,
À1
3
4
cmÀ1):
(CO) 1321 cm
.
4JHH = 1.0 Hz), 7.30 (dd, 1 H, H5, JHH = 4.0 Hz, JHH = 8.0 Hz), 7.41
~
m
(dd, 1 H, H2, JHH = 8.0 Hz, JHH = 8.0 Hz), 8.12 (dd, 1 H, H4, JHH
=
3
4
3
2.4. Synthesis of [AgOC6H4-2-CHO] (3b)
8.0 Hz, 4JHH = 2.0 Hz), 8.46 (dd, 1 H, H6, 3JHH = 4.0 Hz, 4JHH = 2.0 Hz).
3
13C{1H} NMR (CDCl3):
d
13.7 (CH3), 24.3 (d, JCP = 15.0 Hz,
2
Complex 3b was synthesized in the same manner as 3a (Section
2.3): Salicylaldehyde (2b) (0.72 g, 5.9 mmol), [AgNO3] (1) (1.0 g,
5.9 mmol), and NEt3 (0.60 g, 5.9 mmol). After appropriate work-
up, 3b could be isolated as a yellow, moisture and temperature
sensitive solid. Yield: 0.22 g (1.0 mmol, 16% based on 2b).
Anal. Calc. for C7H5AgO2 (228.98): C, 36.56; H, 2.19. Found: C,
~
CH2CH2CH2CH3), 25.9 (d, JCP = 20.0 Hz, CH2CH2CH2CH3), 28.2 (d,
1JCP = 5.0 Hz, CH2CH2CH2CH3), 109.5 (C7), 113.8 (C5), 129.9 (C6),
130.5 (C4), 137.7 (C3), 141.6 (C9), 146.0 (C1), 164.4 (C8). 31P{1H}
NMR (CDCl3): d -3.0. TG: Tbegin = 130 °C, Tend = 400 °C,
Dm = 75.8%.
2.9. Synthesis of [nBu3PAgOC6H4-2-CHO] (6b)
36.14; H, 2.16%. Mp: 116 °C (decomp.). IR (KBr, cmÀ1):
m (CH)
À1
~
~
~
(C@C) 1600, 1525, (CO) 1149 cm
2756,
m
(CO) 1669,
m
m
.
Complex 6b was prepared using the same synthesis methodol-
ogy as described for 6a (Section 2.8), however, as solvent dichloro-
methane was used: nBu3P (4) (259 mg, 1.3 mmol), 3b (300 mg,
1.3 mmol, 2% excess based on 4). After appropriate work-up, 6b
could be isolated as pale yellow oil which best should be stored
at À30 °C, otherwise decomposition may occur. Yield: 489 mg
(1.2 mmol, 89% based on 4).
2.5. Synthesis of [AgOC6H4-2-Cl] (3c)
Complex 3c was prepared as described for the preparation of 3a
(Section 2.3): 2-chlorophenol (2c) (0.76 g, 5.9 mmol), [AgNO3] (1)
(1.0 g, 5.9 mmol), and NEt3 (0.60 g, 5.9 mmol). After appropriate

A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
3
Anal. Calc. for C19H32AgO2P (432.28) C, 52.91; H, 7.48. Found: C,
52.73; H, 7.67%. IR (NaCl, cmÀ1):
m
Found: C, 48.83; H, 7.22; N, 3.07%. Mp: 54 °C. IR (KBr, cmÀ1):
~
~ ~
(CH) 2712 m (CO) 1673, m (C@C)
1596, 1530,
(CO) 1143 cmÀ1. 1H NMR (CDCl3): d 0.90 (t, 9 H, CH3,
~
m
JHH = 7.0 Hz), 1.31–1.73 (m, 18 H, CH2CH2CH2CH3), 6.54 (ddd, 1 H,
(CDCl3): d 0.90 (t, 9 H, CH3, JHH = 7.0 Hz), 1.30–1.73 (m, 18 H,
3
3
4
3
3
H3, JHH = 7.3 Hz, JHH = 7.3 Hz, JHH = 1.0 Hz), 6.76 (d, 1 H, H1,
3JHH = 8.5 Hz), 7.20–7.35 (m, 2 H, H2, H4), 9.73 (bs, 1 H, CHO).
13C{1H} NMR (CDCl3): d 13.7 (CH3), 24.3 (d, 3JCP = 14.0 Hz, CH2CH2-
CH2CH2CH2CH3), 6.46 (ddd, 1 H, H2, JHH = 8.4 Hz, JHH = 6.8 Hz,
3
4
4JHH = 1.3 Hz), 6.92 (dd, 1 H, H4, JHH = 8.5 Hz, JHH = 1.3 Hz), 7.21
(ddd, 1 H, H3, JHH = 8.6 Hz, JHH = 6.8 Hz, JHH = 1.9 Hz) 7.94 (dd,
3
3
4
2
1
3
4
C
H2CH3), 25.9 (d, JCP = 22.0 Hz, CH2CH2CH2CH3), 27.9 (d, JCP
=
1 H, H1, JHH = 8.6 Hz, JHH = 1.9 Hz). 13C{1H} NMR (CDCl3): d 14.0
3
2
4.0 Hz, CH2CH2CH2CH3), 113.7 (C6), 123.5 (C4), 135.8 (C3), 144.3
(CH3), 24.4 (d, JCP = 15.0 Hz, CH2CH2CH2CH3), 25.2 (d, JCP =
1
(C5), 194.5 (CHO). 31P{1H} NMR (CDCl3): d À0.5 (bd, J107Ag31P
=
22.0 Hz, CH2CH2CH2CH3), 28.0 (CH2CH2CH2CH3), 113.8 (C6), 126.5
1
700 Hz), À0.5 (bd, J109Ag31P = 775 Hz).
(C4), 126.7 (C3), 135.4 (C2), 138.2 (C5). 31P{1H} NMR (CDCl3): d
1
1
0.2 (d, J107Ag31P = 689 Hz), 0.2 (d, J109Ag31P = 785 Hz). TG: Tbegin
102 °C, Tend = 208 °C, m = 18.0%; Tbegin = 208 °C, Tend = 349 °C,
m = 43.1%; Tbegin = 349 °C, Tend = 529 °C, m = 2.1%; Tbegin
529 °C, Tend = 877 °C, m = 7.1%. DSC: Peak 218 °C, H = À423.3
J/g; Peak 285 °C, H = 50.3 J/g.
=
2.10. Synthesis of [nBu3PAgOC6H4-2-Cl] (6c)
D
D
D
=
D
D
Complex 6c was synthesized as described for the preparation of
6a (Section 2.8) in dichloromethane as solvent: nBu3P (4) (23 mg,
0.6 mmol), 3c (146 mg, 0.6 mmol, 2% excess based on 4). After
appropriate work-up, 6c could be isolated as a colorless solid
which should best be stored at À30 °C, otherwise decomposition
upon formation of elemental silver may occur. Yield: 184 mg
(0.4 mmol, 68% based on 4).
D
2.13. Synthesis of [(nBu3P)2AgOC9H6N] (7a)
nBu3P (4) (610 mg, 3.0 mmol) was added in a single portion to
3a (390 mg, 1.5 mmol) suspended in 40 mL of diethyl ether at
25 °C. After the reaction mixture was stirred for 2 h at this temper-
ature it was filtrated through a pad of Celite. Removal of all vola-
tiles in oil-pump vacuum produced 7a as orange oil. Yield:
945 mg (1.4 mmol, 96% based on 3a).
Anal. Calc. for C18H31AgClOP (437.73): C, 49.39; H, 7.14. Found:
~
C, 49.06; H, 7.24%. Mp: 63 °C (decomp.). IR (KBr, cmÀ1):
m
(C@C)
~
1576, 1468,
m
(CO) 1310 cmÀ1
.
1H NMR (CDCl3): d 0.93 (t, 9 H,
CH3, JHH = 7.1 Hz), 1.34–1.74 (m, 18 H, CH2CH2CH2CH3), 6.44
3
3
4
Anal. Calc. for C33H60AgNOP2 (656.66) C, 60.36; H, 9.21; N, 2.13.
(ddd, 1 H, H2, JHH = 7.6 Hz, JHH = 7.2 Hz, JHH = 1.6 Hz), 6.88 (dd,
3
4
3
Found: C, 60.04; H, 9.25; N, 2.30%. IR (NaCl, cmÀ1):
m
(C@C) 1593,
m
~
~
1 H, H1, JHH = 8.1 Hz, JHH = 1.8 Hz), 7.04 (ddd, 1 H, H3, JHH
=
3
4
3
(CO), 1332 cmÀ1
.
1H NMR (CDCl3): d 0.80 (t, 18 H, CH3, JHH
=
8.1 Hz, JHH = 7.2 Hz, JHH = 1.8 Hz) 7.24 (dd, 1 H, H4, JHH = 8.0 Hz,
3
7.0 Hz), 1.22–1.51 (m, 36 H, CH2CH2CH2CH3), 6.85 (dd, 1 H, H1,
4JHH = 1.8 Hz). 13C{1H} NMR (CDCl3): d 13.8 (CH3), 24.4 (d, JCP
=
4
3
4
2
3JHH = 8.0 Hz, JHH = 1.0 Hz), 6.99 (dd, 1 H, H3, JHH = 8.0 Hz, JHH
=
14.0 Hz, CH2CH2CH2CH3), 25.3 (d, JCP = 26.0 Hz, CH2CH2CH2CH3),
27.9 (CH2CH2CH2CH3), 114.1 (C6), 120.8 (C2), 121.0 (C4), 128.2
(C5), 129.1 (C3), 157.0 (C1). 31P{1H} NMR (CDCl3): d 0.7 (d,
3
4
1.0 Hz), 7.22 (dd, 1 H, H5, JHH = 4.0 Hz, JHH = 8.0 Hz), 7.33 (dd, 1
3
4
3
H, H2, JHH = 8.0 Hz, JHH = 8.0 Hz), 8.03 (dd, 1 H, H4, JHH = 8.0 Hz,
3
4
1
4JHH = 2.0 Hz), 8.46 (dd,
1
H, H6, JHH = 4.0 Hz, JHH = 2.0 Hz).
1J107Ag31P = 656 Hz), 0.7 (d, J109Ag31P = 755 Hz). TG: Tbegin = 142 °C,
13C{1H} NMR (CDCl3):
d
13.5 (CH3), 24.3 (d, JCP = 13.0 Hz,
3
Tend = 383 °C,
Dm = 66.2%; Tbegin = 516 °C, Tend = 672 °C, Dm = 2.8%.
2
CH2CH2CH2CH3), 25.8 (d, JCP = 7.0 Hz, CH2CH2CH2CH3), 27.4 (d,
1JCP = 8.0 Hz, CH2CH2CH2CH3), 109.7 (C3), 113.0 (C5), 120.0 (C8),
128.8 (C4), 130.3 (C6), 136.0 (C7), 141.9 (C1), 145.1 (C9), 162.7
(C2). 31P{1H} NMR (CDCl3): d -3.0. TG: Tbegin = 100 °C, Tend = 350 °C,
2.11. Synthesis of [nBu3PAgOC6H4-2-C„N] (6d)
Complex 6d was synthesized in the same manner as 6a (Section
2.8): Solvent dichloromethane, nBu3P (4) (0.89 g, 4.4 mmol), 3d
(1.01 g, 4.5 mmol, 2% excess based on 4). After appropriate work-
up, 6d could be isolated as an off-white solid. Yield: 1.64 g
(3.83 mmol, 87% based on 4). Storage at À30 °C is advisable to pre-
vent significant decomposition.
D
m = 83.2%.
2.14. Synthesis of [(nBu3P)2AgOC6H4-2-CHO] (7b)
Complex 7b was synthesized as described for 7a (Section 2.13):
dichloromethane, nBu3P (4) (320 mg, 1.6 mmol), and 3b (187 mg,
0.8 mmol). After appropriate work-up, 7b could be isolated as yel-
low oil. Yield: 481 mg (0.8 mmol, 92% based on 3b). It is advisable
to store 7b at À30 °C to prevent decomposition to elemental silver.
Anal. Calc. for C31H59AgO2P2 (645.63): C, 59.53; H, 9.21. Found:
Anal. Calc. for C19H31AgNOP (428.29): C, 53.28; H, 7.30; N, 3.27.
~
Found: C, 52.93; H, 7.36; N, 3.26%. Mp: 35 °C. IR (KBr, cmÀ1):
m
~
~
(C„N) 2207,
m
(C@C) 1598, 1538, 1472,
m
(CO) 1275 cmÀ1
.
1H
NMR (CDCl3): d 0.91 (t, 9 H, CH3, JHH = 7.0 Hz), 1.30–1.76 (m, 18
3
3
H, CH2CH2CH2CH3), 6.47 (ddd, 1 H, H2, JHH = 8.0 Hz, JHH = 7.0 Hz,
C, 59.57; H, 9.86%. IR (NaCl, cmÀ1):
m
(CH) 2712,
m
(CO) 1645,
m
~
~
~
4JHH = 1.0 Hz), 6.80 (dd, 1 H, H4, JHH = 8.5 Hz, JHH = 0.3 Hz), 7.25
3
4
(CO) 1141 cmÀ1
.
1H NMR (CDCl3): d 0.87 (t,
~
(C@C) 1599, 1524,
m
(ddd, 1 H, H3, JHH = 8.7 Hz, JHH = 7.0 Hz, JHH = 1.9 Hz) 7.32 (dd,
3
3
4
18 H, CH3, JHH = 7.0 Hz), 1.26–1.65 (m, 36 H, CH2CH2CH2CH3),
1 H, H1, JHH = 7.6 Hz, JHH = 1.9 Hz). 13C{1H} NMR (CDCl3): d 13.8
3
3
3
4
6.45 (dd, 1 H, H3, JHH = 7.3 Hz, JHH = 7.3 Hz), 6.70 (d, 1 H, H1,
3
2
3JHH = 8.5 Hz), 7.21 (ddd,
1
H, H2, JHH = 7.7 Hz, JHH = 7.7 Hz,
(CH3), 24.4 (d, JCP = 15.0 Hz, CH2CH2CH2CH3), 24.8 (d, JCP
=
3
3
4JHH = 1.9 Hz), 7.46 (dd, 1 H, H4, JHH = 7.9 Hz, JHH = 1.9 Hz), 10.15
20.0 Hz, CH2CH2CH2CH3), 27.8 (CH2CH2CH2CH3), 99.6 (C2), 113.9
(C„N), 120.9 (C6), 121.9 (C4), 132.5 (C3), 134.3 (C5), 172.1
3
4
(1 H, CHO). 13C{1H} NMR (CDCl3): d 13.8 (CH3), 24.5 (d, JCP
=
3
1
(C1). 31P{1H} NMR (CDCl3): d 0.2 (d, J107Ag31P = 677 Hz), 0.2
2
12.0 Hz, CH2CH2CH2CH3), 25.1 (d, JCP = 13.0 Hz, CH2CH2CH2CH3),
27.7 (CH2CH2CH2CH3); further resonance signals could not be de-
tected, due to the low stability of 7b. 31P{1H} NMR (CDCl3): d 0.2.
1
(d, J109Ag31P = 780 Hz).
2.12. Synthesis of [nBu3PAgOC6H4-2-NO2] (6e)
TG: Tbegin = 103 °C, Tend = 239 °C,
D
m = 50.9%; Tbegin = 239 °C, Tend
m = 7.6%.
=
289 °C, m = 1.3%; Tbegin = 289 °C, Tend = 886 °C,
D
D
Complex 6e was prepared as described in Section 2.8: Solvent
dichloromethane, nBu3P (4) (132 mg, 0.7 mmol), 3e (164 mg,
0.7 mmol, 2% excess based on 4). After appropriate work-up, 6e
could be isolated as an orange solid. Yield: 267 mg (0.6 mmol,
91% based on 4). It is advisable to store 6e at À30 °C to provide
decomposition.
2.15. Synthesis of [(nBu3P)2AgOC6H4-2-Cl] (7c)
Complex 7c was synthesized as described in Section 2.13:
dichloromethane, nBu3P (4) (158 mg, 0.8 mmol), 3c, (92 mg,
0.4 mmol). After appropriate work-up, 7c could be isolated as

4
A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
3
3
off-white oil. Storage at À30 °C is advised (vide supra). Yield:
247 mg (0.4 mmol, 99% based on 3c).
3JPH = 13.6 Hz), 6.55 (ddd, 1 H, H3, JHH = 7.9 Hz, JHH = 6.9 Hz,
4JHH = 1.0 Hz), 6.76 (dd, 1 H, H1, JHH = 8.0 Hz, JHH = 1.0 Hz), 7.24–
3
4
Anal. Calc. for C30H58AgClOP2 Â 2/3 CH2Cl2 (640.04): C, 52.65; H,
7.34 (m, 2 H, H2, H4), 9.62 (bs, 1 H, CHO). 13C{1H} NMR (CDCl3): d
8.55. Found: C, 52.60; H, 8.61%. IR (NaCl, cmÀ1):
m
(C@C) 1575,
51.7 (d, CH3, JCP = 5.0 Hz), 113.8 (C6), 123.3 (C2), 124.0 (C4),
2
~
(CO) 1316 cmÀ1
.
1H NMR (CDCl3): d 0.85 (t, 18 H, CH3,
136.2 (C5), 137.2 (C3), 195.2 (CHO); C1 could not be detected un-
der the conditions of the measurement applied. 31P{1H} NMR
(CDCl3): d 131.3 (bs).
~
1466,
m
JHH = 7.0 Hz), 1.27–1.68 (m, 36 H, CH2CH2CH2CH3), 5.28 (2 H,
3
3
4
CH2Cl2), 6.43 (ddd, 1 H, H2, JHH = 7.8 Hz, JHH = 6.3 Hz, JHH
=
1.5 Hz), 6.88–7.00 (m, 2 H, H3, H4), 7.19 (dd, 1 H, H1, JHH = 7.1 Hz,
3
4JHH = 1.5 Hz). 13C{1H} NMR (CDCl3): d 13.8 (CH3), 24.5 (d, JCP
=
3
2
2.19. Synthesis of [(MeO)3PAgOC6H4-2-NO2] (8b)
13.0 Hz, CH2CH2CH2CH3), 25.0 (d, JCP = 17.0 Hz, CH2CH2CH2CH3),
27.8 (CH2CH2CH2CH3), 53.5 (CH2Cl2), 115.4 (C6), 119.9 (C2),
121.9 (C4), 128.2 (C5), 129.5 (C3). 31P{1H} NMR (CDCl3): d À5.8.
Complex 8b was synthesized in the same manner as described
earlier for 7a (Section 2.13): (MeO)3P (5a) (230 mg, 1.9 mmol), 3e
(467 mg, 1.9 mmol, 2% excess based on 5a). After appropriate
work-up, 8b could be isolated as a yellow solid. Yield: 481 mg
(1.3 mmol, 70% based on 5a). Storage at 0 °C is advisable to prevent
decomposition.
2.16. Synthesis of [(nBu3P)2AgOC6H4-2-C„N] (7d)
Complex 7d was prepared as described in Section 2.13: nBu3P
(4) (1.72 g, 8.5 mmol), 3d, (962 mg, 4.3 mmol). 7d could be isolated
as yellow-brown oil which should be stored at 0 °C to prevent
decomposition. Yield: 2.41 g (3.8 mmol, 90% based on 3d).
Anal. Calc. for C31H58AgNOP2 Â 0.2 CH2Cl2 (630.60): C, 57.86; H,
~
Anal. Calc. for C9H13AgNO6P (369.98) C, 29.21; H, 3.54; N, 3.79.
~
m (C@C) 1610,
Found: C, 29.20; H, 3.55; N, 3.54%. IR (KBr, cmÀ1):
~
m
1540,
(NO) 1499, 1326,
m
(CO) 1244 cmÀ1
~
.
1H NMR (CDCl3): d
3.54 (d, 9 H, CH3, JPH = 4.0 Hz), 6.46 (ddd, 1 H, H2, JHH = 8.4 Hz,
3
3
9.09; N, 2.16. Found: C, 57.90; H, 9.43; N, 2.80%. IR (NaCl, cmÀ1):
m
3JHH = 6.8 Hz, JHH = 1.5 Hz), 7.00 (dd, 1 H, H4, JHH = 8.6 Hz, JHH
=
=
4
3
4
(CO) 1277 cmÀ1. 1H NMR
~
~
m
(C„N) 2204,
m
(C@C) 1594, 1533, 1470,
1.9 Hz), 7.21 (ddd, 1 H, H3, JHH = 7.7 Hz, JHH = 7.7 Hz, JHH
3
3
4
(CDCl3): d 0.78 (t, 18 H, CH3, JHH = 7.0 Hz), 1.17–1.60 (m, 36 H,
1.9 Hz), 7.93 (dd, 1 H, H1, JHH = 8.5 Hz, JHH = 1.8 Hz). 13C{1H}
NMR (CDCl3): d 51.5 (CH3), 114.0 (C3), 126.7 (C6), 126.9 (C4),
135.4 (C2), 137.9 (C5), 167.2 (C1). 31P{1H} NMR (CDCl3): d 129.9.
3
4
CH2CH2CH2CH3), 5.19 (2 H, CH2Cl2), 6.11 (dd, 1 H, H2, 3JHH = 7.3 Hz,
3
3JHH = 7.3 Hz), 6.51 (d, 1 H, H4, JHH = 8.5 Hz),7.00 (ddd, 1 H, H3,
3
4
3JHH = 7.8 Hz, JHH = 7.8 Hz, JHH = 1.9 Hz), 7.10 (dd,
1
H, H1,
4
TG: Tbegin = 105 °C, Tend = 239 °C,
D
m = 50.9%; Tbegin = 239 °C, Tend
m = 7.6%.
=
3JHH = 7.8 Hz, JHH = 1.8 Hz). 13C{1H} NMR (CDCl3): d 13.6 (CH3),
24.3 (bs, CH2CH2CH2CH3), 24.8 (bs, CH2CH2CH2CH3), 27.4 (CH2CH2-
CH2CH3), 53.4 (CH2Cl2), 98.9 (C2), 110.9 (C„N), 121.1 (C6),
122.6 (C4), 132.5 (C3), 133.3 (C5), C1 could not be detected
under the measurement conditions applied. 31P{1H} NMR (CDCl3):
d À7.1.
289 °C, m = 1.3%; Tbegin = 289 °C, Tend = 886 °C,
D
D
2.20. Synthesis of [((MeO)3P)2AgOC6H4-2-NO2] (9)
For the synthesis of 9 see Section 2.13: (MeO)3P (5a): (119 mg,
1.0 mmol), 3e (118 mg, 0.5 mmol). After appropriate work-up, the
title compound could be isolated as red oil. Yield: 202 mg
(0.4 mmol, 85% based on 3e). Storage at À30 °C is advisable due
to significant decomposition to elemental silver may be observed.
Anal. Calc. for C12H22AgNO9P2 (494.11): C, 29.17; H, 4.49; N,
~
2.17. Synthesis of [(nBu3P)2AgOC6H4-2-NO2] (7e)
For details of synthesizing 7e see Section 2.13: nBu3P (4)
(386 mg, 1.9 mmol), 3e (235 mg, 1.0 mmol). After appropriate
work-up, 7e could be isolated as red oil. Complex 7e should best
be stored at 0 °C otherwise decomposition may occur upon forma-
tion of elemental silver. Yield: 611 mg (0.9 mmol, 98% based on
3e).
2.84. Found: C, 29.67; H, 4.44; N, 3.15%. IR (NaCl, cmÀ1):
m (C@C)
~
m
~
m
1601, 1545,
(NO) 1494, 1332,
(CO) 1249 cmÀ1. 1H NMR (CDCl3):
d 3.64 (d, 18 H, CH3, 3JPH = 12.8 Hz), 6.47 (dd, 1 H, H2, 3JHH = 7.8 Hz,
3JHH = 7.7 Hz), 6.89 (dd, 1 H, H4, JHH = 8.8 Hz, JHH = 1.0 Hz), 7.28
3
4
(ddd, 1 H, H3, JHH = 6.0 Hz, JHH = 6.0 Hz, JHH = 1.9 Hz), 7.96 (dd,
Anal. Calc. for C30H58AgNO3P2 (650.59): C, 55.38; H, 8.99; N,
~
3
3
4
2.15. Found: C, 55.16; H, 9.24; N, 1.94%. IR (NaCl, cmÀ1):
m
(C@C)
3
4
1 H, H1, JHH = 8.8 Hz, JHH = 1.9 Hz). 13C{1H} NMR (CDCl3): d 51.3
(CO) 1248 cmÀ1. 1H NMR (CDCl3):
2
~
~
m
1603, 1536,
m
(NO) 1503, 1324,
(d, CH3, JCP = 5.0 Hz), 114.1 (C6), 126.0 (C4), 126.6 (C3), 135.6
(C5), 136.7 (C2), 166.3 (C1). 31P{1H} NMR (CDCl3): d 131.6.
2.21. Synthesis of [(CF3CH2O)3PAgOC6H4-2-NO2] (10)
d
0.86 (t, 18 H, CH3, JHH = 6.9 Hz), 1.24–1.61 (m, 36 H,
3
3
CH2CH2CH2CH3), 6.11 (dd, 1 H, H4, JHH = 7.8 Hz, JHH = 7.8 Hz),
6.66 (dd, 1 H, H3, JHH = 8.7 Hz, JHH = 1.0 Hz), 7.04 (ddd, 1 H, H2,
3
4
3JHH = 8.7 Hz, JHH = 6.7 Hz, JHH = 1.9 Hz), 7.84 (dd,
1
H, H1,
3
4
3JHH = 8.6 Hz, JHH = 1.9 Hz). 13C{1H} NMR (CDCl3): d 13.8 (CH3),
24.5 (bs, CH2CH2CH2CH3), 25.0 (bs, CH2CH2CH2CH3), 27.4
(CH2CH2CH2CH3), 110.9 (C6), 127.1 (C4), 127.9 (C3), 134.3 (C2),
136.8 (C5), 169.9 (C1). 31P{1H} NMR (CDCl3): d À7.4. TG: Tbe-
4
Complex 10 was prepared as described in Section 2.13:
(CF3CH2O)3P (5b) (170 mg, 1.2 mmol), 3e (134 mg, 0.4 mmol, 2%
excess based on 5b). After appropriate work-up, 10 could be iso-
lated as a yellow solid. Yield: 276 mg (0.5 mmol, 93% based on
5b). Storage at 0 °C is advisable otherwise decomposition may oc-
cur to give elemental silver.
gin = 121 °C, Tend = 216 °C,
m = 34.8%; Tbegin = 276 °C, Tend = 867 °C,
216 °C, H = À492.1 J/g; Peak 299 °C, H = 77.1 J/g.
D
m = 38.9%; Tbegin = 216 °C, Tend = 276 °C,
D
D
m = 7.1%. DSC: Peak
D
D
Anal. Calc. for C12H10AgF9NO6P (574.04): C, 25.11; H, 1.76; N,
2.18. Synthesis of [(MeO)3PAgOC6H4-2-CHO] (8a)
2.44. Found: C, 24.25; H, 1.98; N, 2.58%. Mp: 108 °C. IR (KBr,
cmÀ1):
m
(C@C) 1612, 1540,
m
(NO) 1499, 1331,
m
~
~
~
(CO) 1244
For the synthesis of complex 8a see Section 2.13: (MeO)3P (5a)
(113 mg, 0.9 mmol), 3a (220 mg, 1.0 mmol, 2% excess based on 5a).
After appropriate work-up, 8a could be isolated as a yellow solid. It
is advisable to store 8a at À30 °C to prevent decomposition into sil-
ver. Yield: 269 mg (0.8 mmol, 84% based on 5a).
cmÀ1
.
1H NMR (CDCl3): d 3.90–4.20 (m, 6 H, CH2), 6.73 (dd, 1 H,
H2, JHH = 7.5 Hz, JHH = 7.5 Hz), 7.16 (d, 1 H, H4, JHH = 8.5 Hz),
3
3
3
7.39 (dd, 1 H, H3, JHH = 7.7 Hz, JHH = 7.7 Hz), 7.97 (dd, 1 H, H1,
3
3
3JHH = 8.5 Hz, JHH = 1.5 Hz). 13C{1H} NMR (CDCl3): d 61.7 (qd, CH2,
4
2JCF = 38.0 Hz, JCp = 5.0 Hz), 116.4 (C3), 122.5 (q, CF3, JCF
=
2
1
Anal. Calc. for C10H14AgO5P (354.04): C, 33.92; H, 3.99. Found: C,
269.0 Hz), 126.3 (C4), 126.8 (C5), 136.3 (C3); C1 and C2 could not
be detected under the measurement conditions performed.
31P{1H} NMR (CDCl3): d 127.9.
33.83; H, 3.94%. IR (KBr, cmÀ1):
m
(CH) 2756,
m
(CO) 1671, (C@C)
m
~
~
~
1592, 1527,
(CO) 1148 cmÀ1. 1H NMR (CDCl3): d 3.70 (d, 9 H, CH3,
~
m

A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
5
Table 1
Complexes 6–10.
2.22. X-ray crystallography of 8b and 10
The preparation of suitable single crystals was done in perfluo-
roalkyl ether 216 (Riedel-de Haën) for protection against air and
moisture. Data were collected with a Bruker AXS Smart 1k CCD dif-
Compd.
L
m
R
Yielda (%)
6a
6b
6c
6d
6e
7a
7b
7c
7d
7e
8a
8b
9
PnBu3
1
1
1
1
1
2
2
2
2
2
1
1
2
1
C9H6N
C6H4-2-CHO
C6H4-2-Cl
C6H4-2-C„N
C6H4-2-NO2
C9H6N
C6H4-2-CHO
C6H4-2-Cl
C6H4-2-C„N
C6H4-2-NO2
C6H4-2-CHO
C6H4-2-NO2
C6H4-2-NO2
C6H4-2-NO2
98
89
68
87
91
96
92
99
90
98
84
70
85
93
PnBu3
PnBu3
fractometer at 183 K (8b) and 298 K (10). Mo K
a radiation
PnBu3
(k = 0.71073 Å) was used. The structures were solved by direct
methods using SHELXS-97, [13,14] and refined by full-matrix least-
squares procedures on F2 using SHELXL-97. [15] All non-hydrogen
atoms were refined anisotropycally. All hydrogen atoms were re-
fined using a riding model. In 10 five CH2CF3 groups of the
P(OCH2CF3)3 ligands are disordered and have been refined to split
occupancies of 0.80/0.20 (C13, C14, F1–F3), 0.56/0.44 (C15, C16,
F4–F6), 0.57/0.43 (C17, C18, F7–F9), 0.54/0.46 (C19, C20, F10–
F12) and 0.54/0.46 (C23, C24, F16–F18), respectively. The asym-
metric unit contains in both structures half of the tetramer.
PnBu3
PnBu3
PnBu3
PnBu3
PnBu3
PnBu3
P(OMe)3
P(OMe)3
P(OMe)3
P(OCH2CF3)3
10
a
Based on silver(I) phenolates 3a–3e.
3. Results and discussion
upon exposure to light at 25 °C (vide supra). While 3a–3e are insol-
uble in most common organic solvents, metal–organic 6–10 dis-
solve in tetrahydrofuran, dichloromethane and diethyl ether.
3.1. Syntheses und characterization of complexes 3–9
As synthesis methodology for the preparation of phosphane and
phosphite silver(I) phenolates [LmAgOR] (6–10) (Table 1) we
decided to use as starting materials metal–organic [AgOR] (3a,
R = C9H6N; [12a] 3b, R = C6H4-2-CHO, 3c, R = C6H4-2-Cl; 3d,
R = C6H4-2-C„N; 3e R = C6H4-2-NO2 [12b]) which are accessible
upon treatment of [AgNO3] (1) with equimolar amounts of the
alcohols HOR (2a, R = C9H6N; 2b, R = C6H4-2-CHO; 2c, R = C6H4-2-
Cl; 2d, R = C6H4-2-C„N; 2e, R = C6H4-2-NO2) in presence of NEt3
(Eq. (1)). To obtain the desired silver(I) alcoholates in pure form
it was advantageous to use as solvent acetonitrile-ethanol mix-
tures of ratio 1:20 and to carry out the reactions at 0 °C. Within
the course of the reactions silver(I) phenolates 3a–3e precipitated
and hence, could easily be separated by decanting the supernatant
solution. Complexes 3a–3e were obtained as colorless to orange-
red solids in yields between 16 and 88%. These complexes tend
to decompose during minutes (3b, 3c) or days (3a, 3d, 3e) to give
unidentified products at ambient temperature. Thus, storage at
À30 °C is advisable. In addition, 3a–3e are sensitive to light and
should best be maintained in the dark, otherwise decomposition
to elemental silver occurs. Metal–organic 3e is soluble without
decomposition in water.
Et2O or CH2Cl2
[LmAgOR]
+
[AgOR]
m L
4, 5
6 - 10
3
Complexes 3a–3e have been characterized by IR and elemental
analysis. For 6–10 additionally 1H, 13C{1H} and 31P{1H} NMR spec-
troscopic studies, and for 7e temperature-programmed and in situ
molecular beam mass spectrometric experiments were carried out.
For 8b and 10 their molecular structures in the solid state were
established.
The IR spectra of 3b, 6b, 7b and 8a are characterized by a dis-
tinct mCO vibration (aldehyde functionality) at ca. 1650 cmÀ1
~
~
(Experimental Part). The mNO absorption typical for 3e, 6e, 7e, 8b,
9 and 10 is observed at ca. 1500 cmÀ1, while the C„N band for
3d, 6d and 7d is found at 2209, 2207 and 2204 cmÀ1, respectively.
The 1H NMR spectra of 6–10 consist of well-resolved signals
being in agreement with the expected resonance pattern for the or-
ganic phenolates, phosphanes and phosphites present (Section 2).
The signal intensities confirm the composition of the appropriate
complexes.
The most characteristic feature in the 13C{1H} NMR spectra of
6b, 7b and 8a is the resonance signal for the aldehyde carbon atom
at ca. 195 ppm. The C„N unit in 6d and 7d resonates at 113.9 and
110.9 ppm, respectively.
NEt3
[AgOR]
[AgNO3]
H-OR
+
CH3CN / EtOH
The 31P{1H} NMR spectra of 6–10 are of some more interest be-
cause they show that in solution ligand exchange processes occur
(Section 2, Fig. 1). Similar observations were made for comparable
phosphane silver(I) compounds, i.e. [(R3P)Ag-b-diketonates] [15a]
or [(R3P)Ag-carboxylates] [15b]. For all phosphane and phosphite
silver(I) phenolates two super-imposed doublets, with exception
of 6b–6e, are observed at low temperature (1J107Ag31P and
1J109Ag31P), due to coupling of the 31P nucleus with the 107Ag and
109Ag isotopes having natural abundances of 52 and 48%, respec-
tively (Section 2). [16] At 25 °C the 31P{1H} spectra are character-
ized by either broad doublets or broad singlets. Exemplary, the
temperature-dependent 31P{1H} NMR spectra of 10 in the temper-
ature range of 25 to À60 °C are shown in Fig. 1. This behavior cor-
responds to related silver(I) organic compounds, for a detailed
discussion see reference [15b]. As it can be seen from Fig. 1 repre-
sentative 1J107Ag31P and 1J109Ag31P coupling constants of 928 Hz and
1071 Hz are characteristic. Furthermore, it could be demonstrated
that the exchange process becomes faster in the presence of an ex-
cess of phosphane or phosphite molecules [15].
2
3
1
+
-
- HNEt3 NO3
A conventional synthesis route to the phosphane and phosphite
silver(I) phenolates [LmAgOR] (L = PnBu3, m = 1: 6a, R = C9H6N; 6b,
R = C6H4-2-CHO; 6c, R = C6H4-2-Cl; 6d, R = C6H4-2-C„N; 6e, R =
C6H4-2-NO2. m = 2: 7a, R = C9H4; 7b, R = C6H4-2-CHO; 7c, R =
C6H4-2-Cl; 7d, R = C6H4-2-C„N; 7e, R = C6H4-2-NO2. L = P(OMe)3,
m = 1: 8a, R = C6H4-2-CHO; 8b, R = C6H4-2-NO2. m = 2: 9, R =
C6H4-2-NO2. L = P(OCH2CF3)3, m = 1: 10, R = C6H4-2-NO2) is given
by reacting [AgOR] (3a–3e) with Lewis-bases L (4, L = PnBu3; 5a,
L = P(OMe)3; 5b, L = P(OCH2CF3)3) in ratios of 1:1 (synthesis of 6,
8, 10) or 1:2 (synthesis of 7 and 9) in diethyl ether or dichloro-
methane solutions at 0 °C (Eq. (2), Table 1). After appropriate
work-up, complexes 6–10 could be isolated as colorless to pale or-
ange solids (6 and 8–10) or beige to red liquids (7) in excellent
yield (Table 1, Section 2). They are somewhat light-sensitive and
turn grey or brown on prolonged standing at ambient temperature.
This differs from 3a–3e, since these species decompose readily

6
A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
25 °C
0 °C
-20 °C
-40 °C
-60 °C
ppm
136
134
132
130
128
126
124
Fig. 1. Temperature-dependent 31P{1H} NMR spectra of 10 (in CDCl3, temperature
range 25 to À60 °C).
Fig. 3. ORTEP diagram (30% probability level) of 10 with the atom numbering
scheme. The hydrogen atoms and the OCH2CF3 groups at phosphorus are omitted
for clarity. Symmetry transformations used to generate equivalent atoms are
labeled with ‘A’: Àx, y, Àz + 1/2.
Table 2
Selected distances (Å) and angles (°) for complexes 8b and 10a.
8bb
10c
Distances
Ag1–P1
Ag1–O4A
Ag1–O1
Ag1–O4
Ag2–P2
Ag2–O4
Ag2–O1
Ag2–O1A
2.3244(19)
2.337(4)
2.352(4)
2.468(5)
2.338(5)
2.350(5)
2.404(5)
2.459(4)
2.340(2)
2.567(6)
2.411(5)
2.298(5)
2.290(6)
2.343(2)
2.411(5)
2.314(5)
Angles
AgO3P setup around Ag1
P1–Ag1–O1
P1–Ag1–O4
P1–Ag1–O4A
O1–Ag1–O4
O1–Ag1–O4A
O4–Ag1–O4A
Ag4O4 interheterocuban
Ag1–O1–Ag2
Ag1–O1–Ag2A
Ag1–O4–Ag2
Ag1–O4–Ag1A
AgO3P setup around Ag2
P2–Ag2–O1
130.24(12)
115.67(12)
143.00(12)
81.28(16)
83.61(15)
79.47(18)
121.00(15)
144.77(15)
127.09(13)
87.82(18)
83.08(17)
71.8(2)
Fig. 2. ORTEP diagram (50% probability level) of 8b with the atom numbering
scheme. The hydrogen atoms, the OMe groups at phosphorus and the dichloro-
methane molecules as packing solvents are omitted for clarity. Symmetry trans-
formations used to generate equivalent atoms are labeled with ‘A’: Àx + 1, y, Àz + 1/
2.
97.85(17)
94.79(15)
96.13(16)
100.42(18)
90.04(17)
95.13(18)
94.63(19)
107.1(2)
The molecular structures of 8b and 10 in the solid state were
established by single X-ray structure analysis. Single crystals could
be grown from slow diffusion of petroleum ether into a dichloro-
methane solution containing 8b or 10 at À30 °C. A view of com-
plexes 8b and 10 is given in Figs. 2 and 3, respectively. Selected
bond distances (Å) and angles (°) are summarized in Table 2. Crys-
tal data and experimental details of 8b and 10 are presented in Ta-
ble 3.
Essentially, metal–organic 8b and 10 are isostuctural crystalliz-
ing in the monoclinic space group C2/c. Both complexes possess a
crystallographically imposed C2 symmetry with the C2 axis running
through the centre of the Ag2O2 four-membered rings consisting of
the atoms Ag2, O1, Ag2A, O1A and O4, Ag1, O4A, Ag1A for 8b, and
Ag2, O1A, Ag2A, O1 and O4, Ag1A, O4A, Ag1 for 10, respectively.
In both complexes the central Ag4O4 hetero-cubane unit, which
is a most favoured structural motif for phosphane or phosphite
Ag4X4 species (X = O, Br, I), [17–20] is set-up by the silver atoms
132.59(12)
142.30(13)
114.61(12)
82.70(16)
78.26(16)
81.05(15)
127.79(14)
120.19(14)
144.08(15)
82.74(16)
73.4(2)
P2–Ag2–O4
P2–Ag2–O1A
O1–Ag2–O4
O1–Ag2–O1A
O1A–Ag2–O4
88.13(18)
a
Standard deviations are given as the last significant figure(s) in parenthesis.
Symmetry transformations used to generate equivalent atoms: Àx + 1, y, Àz + 1/
b
2.
c
Symmetry transformations used to generate equivalent atoms: Àx, y, Àz + 1/2.
Ag1, Ag2 and the symmetry generated atoms Ag1A and Ag2A as
well as the corresponding oxygen atoms O1, O4, O1A and O4A
(Figs. 1 and 2). The oxygen atoms are thereby acting as four elec-
tron donors and are -bridging three silver(I) ions. Each silver atom
is additionally coordinated by one P(OMe)3 (8b) or P(OCH2CF3)3

A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
7
Table 3
100
Crystal, intensity collection and refinement data for 8b and 10.
8b
10
80
60
40
20
0
Empirical formula
C38H56Ag4Cl4N4O24P4 C12H10AgF9NO6P
Formula weight [g molÀ1
]
1650.03
monoclinic
C2/c
22.717(7)
11.979(4)
21.764(7)
104.196(6)
5742(3)
4
574.05
monoclinic
C2/c
29.715(3)
10.8345(10)
27.175(3)
115.957(2)
7866.3(13)
16
7e
7a
Crystal system
Space group
a (Å)
b (Å)
c (Å)
b (°)
V (Å3)
Z
Crystal size (mm)
0.4 Â 0.3 Â 0.3
0.35 Â 0.3 Â 0.25
Density (calc.) (g cmÀ3
)
1.909
1.939
20
120
220
320
420
Temperature / C°
h Range for data collection /°
Completeness to h (%)
Rint
1.93–26.41
97.4
0.0745
3280
1.52–25.44
97.2
0.0595
Fig. 4. TG trace of 7a (
D
m = 83.2%) and 7e (
D
m = 69.5%) (heating rate 8 K minÀ1
,
nitrogen atmosphere (20 dm3 hÀ1)).
F(0 0 0)
4480
Temperature (K)
Reflections collected
Independent reflections
Parameter
183(2)
16376
6018
358
298(2)
20693
7072
771
Goof (S) based on F2
1.027
1.040
10000
m/z = 202
m/z = 139
m/z = 511
Largest diff. peak and hole /eÁÅÀ3 2.652, À2.740
1.360, À0.922
Absorption coefficient [mmÀ1
]
1.722
0.0715, 0.0966
0.1756, 0.1943
1.219
100
8000
R1: I ꢀ 2
r
(I)/all
(I)/all
0.0715, 0.1134
0.1953, 0.2159
wR2: I ꢀ 2
r
6000
4000
2000
2
2
R1 = [R
(Fo À Fc)/
R
Fo);
wR2 = [
R
(w(Fo À Fc2)2)/
R
(wFo4)]1/2
.
S = [R
w(Fo À Fc2)2]/
(n À p)1/2. n = Number of reflections, p = parameters used.
50
0
(10) ligand resulting in a somewhat distorted tetrahedral sur-
rounding at silver. The Ag–O distances (2.29–2.47 Å) and P-Ag–O
(71.9–71.8°) and O–Ag–O angles (104.8–144.1°) are in agreement
with this structural motif [19,20]. Due to this, also different sil-
ver–phosphorus separations are observed (8b: Ag1–P1
2.3244(19), Ag2–P2 2.338(5) Å; 10: Ag1–P1 2.340(3), Ag2–P2
2.290(6) Å) (Figs. 1 and 2). In both complexes the ortho-positioned
NO2 group is free (Figs. 1 and 2).
0
200
220
240
260
deposition temperature [°C
]
Fig. 5. In situ mass spectrometry: dependence of intensities on the deposition
temperature for detected fragments from 7e (m/z = 511 corresponds to
[(C4H9P)2Ag]+, m/z = 202 to [C4H9P]+, and m/z = 139 to [C6H5NO3]+).
3.2. Thermogravimetric studies
been chosen in accord with the TG experiment of 7e (Fig. 4). This
temperature is slightly below the main decomposition interval
and hence, silver-containing fragments could be detected at this
temperature. In Fig. 5 the signal intensities of selected fragments
in dependence of the deposition temperature are shown. Only at
a deposition temperature of 190 °C, a silver-containing fragment
at m/z = 511 [(C4H9P)2Ag]+ is observed. At deposition temperatures,
the precursor decomposition in the gas phase is dominant as only
fragments from the phosphane ligand (m/z = 202, [C4H9P]+) and the
nitrophenol group (m/z = 139 [C6H5NO3]+) can be detected with
increasing intensity. From these data it can be concluded that 7e
can be considered as a promising CVD precursor candidate. Com-
pared with, for example, [(nBu3P)2AgO2CCH2Ph] a somewhat differ-
ent fragmentation was observed [11], e.g. [(Bu3P)Ag]+ (m/z = 309),
[Bu3P]+ (m/z = 202), and [O2CCH2Ph]+ (m/z = 91, m/z = 136) were
formed, while for 7e ions such as [(Bu3P)2Ag]+ and [C6H5NO3]+
are characteristic.
TG studies (= thermogravimetry) were carried out to obtain first
informations on the decomposition temperature and on the rela-
tive stability of the respective phosphane and phosphite silver(I)
alcoholates. The TG traces show one- or two-step decompositions
(Section 2). Exemplary, the TG traces of 7a and 7e are depicted in
Fig. 4. Both complexes merely display an overall decomposition
starting at 100 (7a) or 120 °C (7e) and ending at 276 (7e) or
350 °C (7a). The mass loss of 83.2% (7a) and 69.5% (7e) is in accor-
dance with the theoretical percentage calculated for the formation
of elemental silver from 7a and 7b, respectively.
3.3. Temperature-dependent and in situ molecular beam mass
spectrometric studies
Temperature-programmed mass spectrometry is
a general
method to determine the volatility and thermal stability of mole-
cules. It has been shown that 7e is volatile but temperature-insta-
ble during the evaporation process, as different fragments
representing 7e can be found in different temperature intervals.
[11] Between 230–310 °C and 340–380 °C, phosphane fragments
have been identified at m/z = 202 [C4H9P+] and m/z = 76 [C3H9P+]
and a nitrophenol fragment at m/z = 139 [C6H5NO3+]. A silver-con-
taining ion (m/z = 309 [C12H27Pg+]) has been detected in the tem-
perature range of 230–310 °C. Additionally, investigations under
typical CVD conditions were analyzed using in situ molecular beam
mass spectrometry. An evaporation temperature of 190 °C has
3.4. Chemical vapor deposition studies
Based on the thermal properties (TGA) we chose 7e as potential
CVD precursor. The CVD experiments were performed in a vertical
cold-wall CVD reactor with stagnation point flow geometry with a
pulsed spray evaporation system. The precursor was evaporated at
190 °C and transported to the deposition zone by a heated quartz
tube with 100 mm length at a pressure of 50 mbar. Argon was used
as carrier gas at a flow rate of 100 sccm. As substrate pre-cleaned

8
A. Jakob et al. / Inorganica Chimica Acta 365 (2011) 1–9
80
70
60
50
40
30
20
10
0
R = C6H4-2-NO2. m = 1, L = P(OCH2CF3)3, R = C6H4-2-NO2. m = 2,
L = P(OMe)3, R = C6H4-2-NO2) by treatment of [AgOR] with PnBu3,
P(OMe)3 or P(OCH2CF3)3 in the ratios of 1:1 or 1:2. The molecular
solid state structure of [(MeO)3PAgOC6H4-2-NO2] and [(CF3CH2)3-
PAgOC6H4-2-NO2] was determined. These metal–organic com-
pounds are isostructural and possess a hetero-cubane Ag4O4 core.
Low-temperature 31P{1H} NMR studies show that the appropriate
phosphane and phosphite complexes are dynamic in solution and
rapidly exchange at room temperature their ligands. Based on
TG, temperature-programmed and in situ molecular beam mass
spectrometry, compound [(nBu3P)2AgOC6H4-2-NO2] was chosen
as CVD (= Chemical Vapor Deposition) precursor in the deposition
of silver onto glass substrates. The resulting silver films were char-
acterized by XRD. The SEM image of a film grown at 350 °C shows a
homogeneous and dense surface with grain sizes of 40 nm.
200
250
300
350
400
deposition temperature [°C
]
Fig. 6. Crystallite size vs. deposition temperature for depositions using metal–
organic 7e.
5. Supplementary material
CCDC 763980 and 763981 contain the supplementary crystallo-
graphic data for complexes 8b and 10, respectively. These data can
be obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Acknowledgements
We are grateful to the Deutsche Forschungsgemeinschaft (SPP-
1119, (International Research Training Group GRK 1215, ‘‘Materials
and Concepts for Advanced Interconnects”) and the Fonds der
Chemischen Industrie for financial support.
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Fig. 7. SEM image of a film deposited at 5 mbar from 7e at 350 °C, thickness
200 nm.
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