Comparative structural studies on silver(I) complexes with tripodal polyphosphines. Crystallographic characterisation of the first infinite chain structures in 2:1 adducts of silver(I) halides with 1,1,1-tris(diphenylphosphinomethyl)ethane

Article abstract of DOI:10.1039/b106021j

The AgX salts [X = Cl, Br, I, NO₃] react with CP₃ [MeC(CH₂PPh₂)₃], PP₃ [P(CH₂CH₂PPh₂)₃] and NP₃ [N(CH₂CH₂PPh₂)₃] in 1:1 stoichiometric ratio to afford complexes Ag(CP₃)X [X = Cl (1), Br (2), I (3)], Ag(PP₃)Cl (4), Ag(NP₃)Cl (6) and Ag(NP₃)(NO₃) (7) where Ag(I) is bound to three P atoms of the ligand. The X-ray crystal structure of complex 6 consists of a mononuclear compound with absence of the N atom of NP₃ in the coordination to the metal. The 1:1 complex obtained by reaction of AgNO₃ with PP₃ was shown by conductivity measurements, mass spectrometry, infrared and NMR spectroscopy to be a dinuclear ionic complex [Ag₂(PP₃)₂](NO₃)₂ (5) where Ag(I) shows three- and four-coordination. The interaction of AgX halides with CP₃ in 2:1 stoichiometric ratio leads to complexes Ag₂(CP₃)X₂ [X = Cl (8), Br (9), I (10)] which were shown by X-ray crystallography to consist of infinite zigzag (X = Cl, I) or linear (X = Br) chains containing three- and four-coordinate Ag(I) and constituting the first examples of such complexes with CP₃. These polymeric chains did not give reaction with another equivalent of AgX to form the Ag₃(CP₃)X₃ [X = Cl, Br, I] complexes. The 2:1 and 3:1 nitrate derivatives Ag₂(PP₃)(NO₃)₂ (11), Ag₂(NP₃)(NO₃)₂ (12), Ag₃(PP₃)(NO₃)₃ (13) and Ag₃(NP₃)(NO₃)₃ (14) show participation of the nitrate anion as ligand finding for 13 two different geometries about Ag(I) in solution. Complexes 13 and 14 react with the corresponding phosphines PP₃ and NP₃ to form complexes 5 and 7, respectively involving ring-closure reactions.

Full text of DOI:10.1039/b106021j

View Article Online / Journal Homepage / Table of Contents for this issue
Comparative structural studies on silver(I) complexes with tripodal
polyphosphines. Crystallographic characterisation of the first
infinite chain structures in 2 : 1 adducts of silver(I) halides with
1,1,1-tris(diphenylphosphinomethyl)ethane†
José A. Montes,a Susana Rodríguez,a Damián Fernández,a M. Inés García-Seijo,a
Robert O. Gouldb and M. Esther García-Fernández*a
a Department of Inorganic Chemistry, University of Santiago de Compostela,
E-15782 Santiago de Compostela, Spain. E-mail: qiegfq@usc.es
b Department of Chemistry, University of Edinburgh, King’s Buildings, West Mains Road,
Edinburgh, UK EH 93 JJ
Received 9th July 2001, Accepted 19th November 2001
First published as an Advance Article on the web 7th February 2002
The AgX salts [X = Cl, Br, I, NO3] react with CP3 [MeC(CH2PPh2)3], PP3 [P(CH2CH2PPh2)3] and NP3
[N(CH2CH2PPh2)3] in 1 : 1 stoichiometric ratio to afford complexes Ag(CP3)X [X = Cl (1), Br (2), I (3)], Ag(PP3)Cl
(4), Ag(NP3)Cl (6) and Ag(NP3)(NO3) (7) where Ag() is bound to three P atoms of the ligand. The X-ray crystal
structure of complex 6 consists of a mononuclear compound with absence of the N atom of NP3 in the coordination
to the metal. The 1 : 1 complex obtained by reaction of AgNO3 with PP3 was shown by conductivity measurements,
mass spectrometry, infrared and NMR spectroscopy to be a dinuclear ionic complex [Ag2(PP3)2](NO3)2 (5) where
Ag() shows three- and four-coordination. The interaction of AgX halides with CP3 in 2 : 1 stoichiometric ratio
leads to complexes Ag2(CP3)X2 [X = Cl (8), Br (9), I (10)] which were shown by X-ray crystallography to consist of
infinite zigzag (X = Cl, I) or linear (X = Br) chains containing three- and four-coordinate Ag() and constituting the
first examples of such complexes with CP3. These polymeric chains did not give reaction with another equivalent of
AgX to form the Ag3(CP3)X3 [X = Cl, Br, I] complexes. The 2 : 1 and 3 : 1 nitrate derivatives Ag2(PP3)(NO3)2 (11),
Ag2(NP3)(NO3)2 (12), Ag3(PP3)(NO3)3 (13) and Ag3(NP3)(NO3)3 (14) show participation of the nitrate anion as ligand
finding for 13 two different geometries about Ag() in solution. Complexes 13 and 14 react with the corresponding
phosphines PP3 and NP3 to form complexes 5 and 7, respectively involving ring-closure reactions.
complexes (X = Cl, Br, I, CN; nЈ = 3) exist in solid state as
Introduction
mononuclear systems with both uni- and bidentate diphos-
The affinity of Ag() for N-donor ligands especially pyridine
phines and coordinated anion. The aminophosphines [L1
=
and its derivatives is well known.1 However, thermodynamic
and spectroscopic studies demonstrate that the silver() com-
plexes with phosphorus donor ligands are far more stable than
with nitrogen donor ligands.2 Depending on the phosphine lig-
and used a wide variety of silver-coordination numbers from
two to the unusual five were found in complexes with different
Ag : ligand stoichiometric ratios. Thus, complexes formed from
silver() salts with monodentate tertiary phosphines in 1 : 1 ratio
can exist as tetrameric,3–5 trimeric5 or dimeric6 systems of gen-
eral formula [{AgX(PR3)}n] (n = 4–2) where the metal achieves
coordination numbers four or three. Reactions of silver() salts
with these ligands in a 1 : 2 ratio generally resulted in the form-
ation of either monomeric [AgX(PR3)2]/[Ag(PR3)2]ϩXϪ,5,7–10 or
dimeric [{AgX(PR3)}2] complexes5,10,11 with four-coordinate
Ag() in the majority of the neutral compounds and two- or
three-coordinate found only when the anion is a weak donor
and/or the substituents on the ligand are bulky.12,13 By complex-
ation of Ag() with diphosphines as Ph2P(CH2)nЈPPh2 (nЈ = 2–3)
in 1 : 2 ratios, ionic and neutral compounds of the types [Ag-
(P–P)2]ϩ 2,14 and [AgX(P–P)2],15 respectively, were formed, the
3,6-bis(diphenylphosphino)pyridazine, L2 = 2,6-bis(diphenyl-
phosphino)pyridine, L3 = (2-diphenylphosphino-6-pyrazol-1-
yl)pyridine] form 3 : 2 and 2 : 2 complexes with AgNO3 or
AgClO4 of the types [Ag2(µ-L1)3(O2NO)2], [Ag2(µ-L2)3](ClO4)2
and [Ag2(µ-L3)2(µ-dppm)](ClO4)2 containing five-(AgP3O2),
three-(AgP3) and five-(AgN2P2Ag) coordinate silver() centres,
respectively.16 Upon reaction of the tripodal triphosphine,
HC(PPh2)3 with Ag(CF3SO3) in the presence of LiClO4, a
triangular silver() complex [Ag3{HC(PPh2)3}2](ClO4)3 was
obtained, with each silver atom being essentially in a linear two-
coordinate geometry.17 Ligands of higher denticity as the linear
polyphosphine Ph2P(CH2)2PPh(CH2)2PPh(CH2)2PPh2 (tetra-
phos) spontaneously self-assemble into a homochiral double-
stranded disilver() helicate of the type [Ag2(tetraphos)2]X2
upon reaction with appropriate silver() salts, where the metal is
four-coordinate.18
The silver() preference for linear two-coordinate and tetra-
hedral geometries can serve to link bridging ligands19 to form
polymeric chains of unusual and desirable properties and with
new coordination modes.20–22 Thus, Fenske and coworkers
reported in 1997 the crystal structure23 of the polymeric chain
complex, [Ag10(µ3-TePh)10(PMe3)2]∞, with tetrahedral coordin-
ation geometry for the phosphorus-bonded silver() centre
(AgPTe3) and three-coordination geometry for the remaining
ones (AgTe3). However, little work has been directed toward the
comparative studies of silver() complexes with pendant
metal being in
a tetrahedral environment. The neutral
† Electronic supplementary information (ESI) available: 31P-{1H}
NMR spectrum of 13; far-IR spectra of 1 and 8; view along the c axis
of the unit cell of 8; fragment of an infinite chain for 8, 9 and 10. See
http://www.rsc.org/suppdata/dt/b1/b106021j/
1110
J. Chem. Soc., Dalton Trans., 2002, 1110–1118
This journal is © The Royal Society of Chemistry 2002
DOI: 10.1039/b106021j

View Article Online
polyphosphines as 1,1,1-tris(diphenylphosphinomethyl)ethane
(CP3),24,25 tris[2-(diphenylphosphino)ethyl]phosphine (PP3) and
tris[2-(diphenylphosphino)ethyl]amine (NP3).26
using a modification of a literature method.29,30 Diphenyl-
phosphine (11 ml, 11.8 g, 62.9 mmol) was added to a suspen-
sion of potassium tert-butoxide (18.1 g, 160.9 mmol) in dry and
freshly distilled THF (250 ml) under argon. The resulting deep
red solution was stirred for 15 min and tris(2-chloroethyl)amine
hydrochloride (5.0 g, 20.8 mmol) was added as a powder. The
mixture was refluxed for 20 h at 80 ЊC, poured into 700 ml of
water and cooled in an ice bath. The ligand precipitated and
was filtered off, recrystallizated from DMF/H2O and washed
with EtOH. Yield: 78%, mp 102 ЊC. Found: C, 77.1; H, 6.9; N,
2.1. Calc. for C42H42NP3: C, 77.1; H, 6.5; N, 2.1%. δP(CDCl3):
Ϫ22.7 (s).
In this work we report the synthesis, structural characteris-
ation and reactivity of 1 : 1, 2 : 1 and 3 : 1 adducts of AgX salts
(X = Cl, Br, I, NO3) with CP3, PP3 and NP3.
Synthesis of complexes
AgLX. 1 : 1 Complexes were prepared with L = CP3, X = Cl
(1), Br (2), I (3); L = PP3, X = Cl (4), NO3 (5); L = NP3, X = Cl
(6), NO3 (7). In each case the reaction involves addition of the
silver() salt to the appropriate ligand using 1 mol equiv. of AgX
per mol of L. Compounds 1–7 were obtained by reaction of
AgX (0.20–0.50 mmol) as a solid when X = Cl, Br, I and in
methanolic solution (10–15 ml) when X = NO3 to a solution of
the ligand (0.20–0.50 mmol) in CH2Cl2 (10–15 ml; L = PP3,
NP3) or CHCl3 (25 ml; L = CP3). The complexes were precipi-
tated with Et2O, filtered off and then dried in vacuo. 1: Yield
68%, white solid, mp 175 ЊC. Found: C, 58.0; H, 5.1. C46H50-
OP3Cl4Ag (Ag(CP3)ClؒEt2OؒCHCl3) requires: C, 57.5; H, 5.2%.
IR νmax/cmϪ1 204vs (Ag–Cl). δP(CDCl3): See Table 1. Λ(DMF):
12.7 ohmϪ1 cm2 molϪ1. 2: Yield 86%, white solid, mp 170 ЊC.
Found: C, 56.9; H, 5.4. C41H45O3P2BrAg (Ag(CP3)Brؒ3H2O)
requires: C, 56.8; H, 5.2%. IR νmax/cmϪ1 133vs (Ag–Br).
δP(CDCl3): Ϫ21.3 [3P, br]. Λ(DMF): 12.0 ohmϪ1 cm2 molϪ1. 3:
Yield 53%, white solid, mp 160 ЊC. Found: C, 51.6; H, 4.7.
C46H50OP3Cl3IAg (Ag(CP3)IؒEt2OؒCHCl3) requires: C, 52.4; H,
4.8%. IR νmax/cmϪ1 118m (Ag–I). δP(CDCl3): Ϫ24.7 [3P, br].
Λ(DMF): 6.7 ohmϪ1 cm2 molϪ1. 4: Yield 84%, white solid, mp
230 ЊC. Found: C, 60.1; H, 5.2. C42.5H43P4Cl2Ag (Ag(PP3)Clؒ
1/2CH2Cl2) requires: C, 59.6; H, 5.0%. IR νmax/cmϪ1 185s (Ag–
Cl). δP(CDCl3, CD2Cl2): See Table 1. Λ(DMF): 87.0 ohmϪ1 cm2
molϪ1. MS (FAB): m/z 779 ([M Ϫ Cl]ϩ, 12%). 5: Yield 86%,
white solid, mp 170 ЊC. Found: C, 58.1; H, 4.8; N, 1.7. C85H86-
P8N2O6Cl2Ag ([Ag2(PP3)2](NO3)2ؒCH2Cl2) requires: C, 57.8; H,
5.0; N, 1.6%. IR νmax/cmϪ1 1383vs asym. (N–O). δP(CD2Cl2):
See Table 1. δAg(CD2Cl2): 1376 [2Ag, m, 1J(107/109AgP) 170, 270].
Λ(DMF/CH3CN): 165.7/273.0 ohmϪ1 cm2 molϪ1. MS (FAB):
m/z 1344 ([M Ϫ 2NO3 Ϫ P]2ϩ, 30%); 779 ([M Ϫ 2NO3 Ϫ L Ϫ
Ag]ϩ, 100%). ESI-MS (ϩ): m/z 779 ([M Ϫ 2NO3]2ϩ, 100%). 6:
Yield 82%, white solid, mp >250 ЊC. Found: C, 63.0; H, 5.8; N,
1.9. C42H42NP3ClAg (Ag(NP3)Cl) requires: C, 63.3; H, 5.3;
N,1.8%. IR νmax/cmϪ1 181m (Ag–Cl). δP(CDCl3): See Table 1.
Λ(DMF/CH3CN): 10.9/8.2 ohmϪ1 cm2 molϪ1. MS (FAB): m/z
762 ([M Ϫ Cl]ϩ, 100%). 7: Yield 63%, white solid, mp >250 ЊC.
Found: C, 61.2; H, 5.3; N, 3.4. C42H42N2P3O3Ag (Ag(NP3)NO3)
requires: C, 61.2; H, 5.1; N, 3.4%. IR νmax/cmϪ1 1484vs, 1316s
(N–O). δP(DMSO-d6): See Table 1. Λ(DMF): 35.6 ohmϪ1 cm2 -
molϪ1. MS (FAB): m/z 762 ([M Ϫ NO3]ϩ, 100%).
The nitrato complexes containing the ligands CP3 or NP3 and
prepared in 1 : 1 stoichiometric ratio showed different struc-
tures in solution from the analogous complexes prepared from
AgX salts (X = Cl, Br, I).27 The structure determination by
X-ray diffraction of Ag(NP3)Cl, here reported, shows that the
ligand is bound to the metal in a tridentate chelating mode
through the three P atoms in a mononuclear complex where
silver() achieves the four-coordination with participation of Cl
as ligand. To our knowledge, except for the reported complex,
Ag3(CP3)(NO3)3,28 no chemistry of Ag() with CP3, PP3 or NP3
in 2 : 1 and 3 : 1 ratios has been previously described. The
reactions of nitrate complexes 2 : 1 and 3 : 1 with phosphine,
carried out in solution, reveal the formation of the correspond-
ing 1 : 1 compounds.
Finally, the crystalline structures of the 2 : 1 adducts,
Ag2(CP3)X2 [X = Cl, Br, I] consist of infinite zigzag (X = Cl, I)
or linear (X = Br) chains, where Ag() achieves simultaneously
and alternatively the four (AgP2X2)- and three (AgX2P)-
coordination, the crystal packing being a function of the
bridging ligand X.
Experimental
General procedures and instrumentation
Solvents were dried by conventional methods, distilled and
kept under argon. CP3 and PP3 were purchased from Strem
Chemicals and Aldrich, respectively. Other reagents were avail-
able of the highest commercial grade and were used as received.
Solvent evaporations were always carried out under vacuum
using a rotary evaporator and a vacuum line. Microanalyses (C,
H, N) were performed at the University of Santiago de Com-
postela. Fast Atom Bombardment (FAB) spectra were obtained
on a KRATOS MS 50 spectrometer using 3-nitrobenzyl alcohol
as the matrix. Electrospray Mass Spectrometry (ESMS)
spectrum was recorded at the University of Barcelona on a
MICROMASS VG-QUATTRO spectrometer using CH3CN/
H2O/formic acid 1% as the mobile phase. Infrared spectra were
recorded at ambient temperature as KBr pellets (4000–500
cmϪ1) and Nujol mulls (500–100 cmϪ1) on a Mattson Cygnus
100 spectrophotometer. The bands are reported as: vs = very
strong, s = strong, m = medium, w = weak and sh = shoulder.
31P-{1H} NMR spectra were recorded on a Bruker AMX-500
spectrometer at 202.46 MHz. 109Ag NMR spectrum was
recorded on a Bruker AMX-500 spectrometer at 23.31 MHz.
Chemical shifts are reported relative to external standard 85%
H3PO4 (31P) and a saturated solution of AgNO3 in D2O (109Ag);
δ = chemical shift in ppm; s = singlet, d = doublet, t = triplet,
dt = doublet of triplets, m = multiplet, br = broad signal,
J = coupling constant in Hz. Conductivities were obtained at 25
ЊC from 10Ϫ3 M solutions in DMF or CH3CN on a WTW
model LF-3 instrument.
Ag2LX2. These complexes were isolated with L = CP3, X = Cl
(8), Br (9), I (10); L = PP3, X = NO3 (11); L = NP3, X = NO3 (12).
The silver() salts were added to the appropriate ligand using
2 mol equiv. of AgX per mol of L. AgX (0.30–1.00 mmol)
was added as a solid (X = Cl, Br, I) or dissolved in methanol
(15–20 ml; X = NO3) to solutions of L (0.15–0.50 mmol) in
CH2Cl2 (10 ml; L = PP3, NP3) or in CHCl3 (25 ml; L = CP3). The
mixtures were stirred for 24 hours and the solids precipitated by
addition of ether. After filtration the solids were dried in vacuo.
8: Yield 59%, white solid, mp >250 ЊC. Found: C, 53.9; H, 5.1.
C45H51P3O2Cl2Ag2 (Ag2(CP3)Cl2ؒEt2OؒH2O): C, 53.9; H, 5.1%.
IR νmax/cmϪ1 211vs, 190sh, 171sh (Ag–Cl). δP(CDCl3): See Table
1. 9: Yield 80%, white solid, mp >250 ЊC. Found: C, 49.1; H,
Synthesis of NP3
Tris(2-diphenylphosphinoethyl)amine (NP3) was prepared
J. Chem. Soc., Dalton Trans., 2002, 1110–1118
1111

View Article Online
Table 1 31P-{1H} NMR data (r.t.) for complexes 1, 4–8, 11–14 and titrations with ligand of 12, 13 and 14
Compound
δ(31P)
1J(107/109Ag31P)/Hz
AgPx
Solvent
Ag(CP3)Cl (1)
Ϫ19.8br
Ϫ20.3br
CDCl3
CDCl3
CDCl3
CD2Cl2
CD2Cl2
CDCl3 ϩ CD3OD
CDCl3
CDCl3 ϩ DMF
CD2Cl2 ϩ DMF
CDCl3 ϩ DMF
Ag2(CP3)Cl2 (8)
Ag(PP3)Cl (4)
Ϫ3.8br
Ag(PP3)Cl (4)a
Ϫ0.5br, 10.0d,b 15.9db
395,b 402b
AgP3
AgP4 AgP3
AgP4, AgP3
[Ag2(PP3)2](NO3)2 (5)
[Ag2(PP3)2](NO3)2 (5)
Ag2(PP3)(NO3)2 (11)
Ag3(PP3)(NO3)3 (13)
Ag3(PP3)(NO3)3 (13)a
13 ϩ 1.0 eq. PP3
13 ϩ 2.0 eq. PP3
13 ϩ 3.0 eq. PP3
Ag(NP3)Cl (6)
Ag(NP3)(NO3) (7)
Ag(NP3)(NO3) (7)
Ag2(NP3)(NO3)2 (12)
12 ϩ 1.0 eq. NP3
12 ϩ 2.0 eq. NP3
12 ϩ 3.0 eq. NP3
12 ϩ 4.0 eq. NP3
Ag3(NP3)(NO3)3 (14)
14 ϩ 1.0 eq. NP3
14 ϩ 2.0 eq. NP3
14 ϩ 3.0 eq. NP3
Ϫ4.7br d, Ϫ0.2dm,b 8.0br dd,b 15.2br ddb
261/176,b 376/433,b 355/420b
175/263, 355/395
1.0dm, 15.1br dd
10.0br, 12.6br, 49.4br
7.4br
7.6br d, 10.4br d
Ϫ3.2br, 7.6br
Ϫ3.1m, 12.4br dd
Ϫ14.9br, Ϫ10.7br, Ϫ2.6br d, 12.4br d
Ϫ19.7dd
Ϫ8.5d
Ϫ4.3dd
Ϫ2.9s
Ϫ8.5d
Ϫ18.4br, Ϫ11.1d
Ϫ18.7br, Ϫ11.6d
Ϫ19.9br, Ϫ11.8d
0.6s
Ϫ2.5s
Ϫ4.1d
512, 752
AgP2, AgP
230, 356/414
191, 442
277/318
344
AgP4, AgP3
AgP4, AgP3
AgP3
AgP3
AgP3
CDCl3
CDCl3
DMSO-d6
CDCl3
CDCl3
351/274
343
273
255
243
AgP3
AgP3
AgP4
AgP4
DMSO-d6
DMSO ϩ CDCl3
336
304
AgP3
AgP3
Ϫ11.0br, Ϫ5.4d
a 4 (233 K), 13 (253 K). b Signals with coupling constants.
4.7. C45H51P3O2Br2Ag2 (Ag2(CP3)Br2ؒEt2OؒH2O) requires: C,
49.5; H, 4.7%. IR νmax/cmϪ1 148sh, 122s (Ag–Br). δP(CDCl3):
Ϫ15.0 [3P, br]. 10: Yield 91%, white solid, mp 190 ЊC (decomp.).
Found: C, 43.9; H, 3.9. C41H46P3O2Cl2Ag2 (Ag2(CP3)I2ؒ2H2O)
requires: C, 43.6; H, 3.8%. IR νmax/cmϪ1 133w, 116s (Ag–I).
Titration of complexes with ligand
Ag2(NP3)(NO3)2. To a solution of Ag2(NP3)(NO3)2 (12) in
CDCl3, solutions containing 1 and 2 molar equivalents of the
ligand in CDCl3 were added. 31P-{1H} NMR spectra were
recorded after additions.
δP(DMSO-d6):Ϫ13.0 [3P, br]. Λ(DMF): 12.1 ohmϪ1 cm2 molϪ1
.
11: Yield 94%, grey solid, mp 215 ЊC (decomp.). Found: C, 49.2;
H, 4.9; N, 2.8. C42H42P4N2O6Ag2 (Ag2(PP3)(NO3)2) requires: C,
49.9; H, 4.9; N, 2.8%. IR νmax/cmϪ1 1384vs, 1304s asym. (N–O).
δP(CDCl3): See Table 1. Λ(DMF): 9.7 ohmϪ1 cm2 molϪ1. MS
(FAB): m/z 950 ([M Ϫ NO3]ϩ, 34%); 888 ([M Ϫ 2NO3]2ϩ, 9%);
779 ([M Ϫ 2NO3 Ϫ Ag]ϩ, 4%). 12: Yield 51%, brown solid, mp
138 ЊC (decomp.). Found: C, 48.6; H, 4.6; N, 4.2. C42.5H43N2-
P3O6ClAg2 (Ag2(NP3)(NO3)2ؒ1/2CH2Cl2) requires: C, 49.2; H,
4.2; N, 4.0%. IR νmax/cmϪ1 1384vs, 1296s, 1293s asym. (N–O).
δP(CDCl3): See Table 1. Λ(DMF): 140.8 ohmϪ1 cm2 molϪ1. MS
(FAB): m/z 933 ([M Ϫ NO3]ϩ, 10%); 871 ([M Ϫ 2NO3]2ϩ, 1%);
762 ([M Ϫ 2NO3 Ϫ Ag]ϩ, 92%).
Ag3L(NO3)3. Solutions of 1, 2 and 3 molar equivalents of the
ligand in CDCl3 were added to solutions of Ag3(PP3)(NO3)3
(13) in DMF and Ag3(NP3)(NO3)3 (14) in DMSO-d6. 31P-{1H}
NMR spectra were recorded after additions.
X-Ray crystallography
Colourless crystals of 6, 8ؒ2DMF, 9 and 10ؒ3DMSO were
mounted on glass fibers and used for data collection. Crystals
data were collected at 291(2) K, using a Bruker SMART CCD
1000 diffractometer (8ؒ2DMF, 9 and 10ؒ3DMSO) and a Stoe
Stadi4 four-circle diffractometer (6). Crystals of 10ؒ3DMSO
were of a lower quality than those of 8ؒ2DMF and 9. This
lowered the precision of the crystal structure which can be
taken to establish chemical connectivity. Graphite mono-
chromated MoKα radiation (λ = 0.71073 Å) was used through-
out. The data were processed with SAINT31 and empirical
absorption correction was made for 8ؒ2DMF, 9 and 10ؒ
3DMSO using SADABS.32 No absorption correction was made
for 6. The structures were solved by direct methods using the
program SHELXS-9733 and refined by full-matrix least-squares
techniques against F 2 using SHELXL-97.34 Positional and
anisotropic atomic displacement parameters were refined for all
non-hydrogen atoms. Hydrogen atoms were placed geometric-
ally and positional parameters were refined using a riding
model. Atomic scattering factors were obtained with the use of
ref. 35. Molecular graphics were obtained from ORTEP-3 for
Windows.36
Ag3LX3. Adducts in 3 : 1 metal : ligand ratio were synthesised
with L = PP3, X = NO3 (13) and L = NP3, X = NO3 (14). 13: A
solution of AgNO3 (1.35 mmol) in methanol (45 ml) was added
dropwise to a solution of PP3 (0.34 mmol) in dry CH2Cl2 (15
ml). After stirring the final solution for 24 hours, a solid precipi-
tated which was filtered off and dried in vacuo. Yield 73%, white
solid, mp 215 ЊC (decomp.). Found: C, 42.0; H, 3.6; N, 3.6.
C42H42P4N3O9Ag3 (Ag3(PP3)(NO3)3) requires: C, 42.7; H, 3.6;
N, 3.6%. IR νmax/cmϪ1 1384vs, 1280s asym. (N–O). δP(CD2Cl2 ϩ
DMF): See Table 1. Λ(DMF): 101.1 ohmϪ1 cm2 molϪ1. MS
(FAB): m/z 950 ([M Ϫ 2NO3 Ϫ Ag]ϩ, 26%); 888 ([M Ϫ 3NO3 Ϫ
Ag]2ϩ, 7%); 779 ([M Ϫ 3NO3 Ϫ 2Ag]ϩ, 100%). 14: A solution of
AgNO3 (0.69 mmol) in methanol (28 ml) was added slowly to a
solution of NP3 (0.23 mmol) in dry CH2Cl2 (10 ml). After stir-
ring for 24 hours, the final solution was filtered off and solvents
were removed in vacuo. The solid formed was recrystallised
from CH2Cl2/Et2O and dried in vacuo. Yield 65%, white solid,
mp 104 ЊC (decomp.). Found: C, 42.3; H, 3.9; N, 4.8. C42.5H43-
N4P3O9ClAg3 (Ag3(NP3)(NO3)3ؒ1/2CH2Cl2) requires: C, 42.3;
H, 3.6; N, 4.6%. IR νmax/cmϪ1 1384vs, 1292vs asym. (N–O).
CCDC reference numbers 173819–173822.
See http://www.rsc.org/suppdata/dt/b1/b106021j/ for crystal-
lographic data in CIF or other electronic format.
Results and discussion
δP(DMSO-d6): See Table 1. Λ(DMF): 182.3 ohmϪ1 cm2 molϪ1
.
Synthesis
MS (FAB): m/z 1104 ([M Ϫ NO3]ϩ, 6%); 931 ([M Ϫ 2NO3 Ϫ
Ag]ϩ, 16%); 762 ([M Ϫ 3NO3 Ϫ 2Ag]ϩ, 100%).
The silver() complexes prepared with ligands CP3, PP3 and NP3
are shown in Scheme 1. Except for Ag(NP3)X [X = Cl (6), NO3
1112
J. Chem. Soc., Dalton Trans., 2002, 1110–1118

View Article Online
ing mode of coordination for CP3 together with the nitrate
anion. The nitrate derivative with PP3 (5) shows a more compli-
cated 31P-{1H} NMR spectrum (Fig. 1). The doublets at δ Ϫ4.7
and 8.0 with integration ratio 1 : 1 in CD2Cl2, disappear when
the spectrum is recorded in CDCl3 ϩ CD3OD (Table 1) and this
is attributable to a coordinating behaviour of CD3OD. The
1J(AgP) coupling constants obtained from the pair of signals
at δ Ϫ0.2 and 15.2 with integration ratio 4 : 2 in CD2Cl2
are 261/176 and 355/420 Hz, respectively, in agreement with
silver() bound to four and three 31P atoms, respectively.15,39
On the other hand, the 109Ag NMR spectrum of 5 in CD2Cl2
(Fig. 2) shows a multiplet centred at δ 137640a analysable as
overlapped multiplets (dt, ddt) with 1J(AgP) values of 170 and
270 Hz also in accordance with AgP4 and AgP3 environments,
respectively. These results are consistent with the presence of
dinuclear species, [Ag2(PP3)2](NO3)2 where one phosphine PP3
can act as tridentate and bridging ligand and the other as tri-
dentate ligand with an uncoordinated phosphorus undergoing
exchange processes with the bridging one (Scheme 2). Thus
Scheme 1 Silver() complexes prepared with tripodal polyphosphine
ligands.
(7)], Ag2(PP3)(NO3)2 (11) and Ag3(PP3)(NO3)3 (13) the other
complexes were obtained as dichloromethane (PP3, NP3), ether
and/or water (CP3) solvates.
Complexes with 1 : 1 metal : ligand ratios were prepared as
chloride (1, 4, 6) or nitrate (Ag(CP3)(NO3),28 5, 7) systems with
CP3, PP3 and NP3. The crystallographic characterisation of
complex 6 was done using crystals obtained by recrystallization
of Ag(NP3)Cl in CH2Cl2/CH3CN. Crystals suitable for X-ray
diffraction studies of Ag2(CP3)Cl2 (8ؒ2DMF) and Ag2(CP3)Br2
(9) were obtained from DMF solutions of Ag(CP3)ClؒEt2Oؒ
CHCl3 (1ؒEt2OؒCHCl3) and Ag(CP3)Brؒ3H2O (2ؒ3H2O) res-
pectively. However, the X-ray structure of complex Ag2(CP3)I2ؒ
3DMSO (10ؒ3DMSO) was determined using crystals grown
(size: 0.34 × 0.17 × 0.07 mm) from DMSO solutions of
Ag2(CP3)I2ؒ2H2O (10ؒ2H2O). The reaction of AgNO3 in
methanol with PP3 and NP3 in dichlorometane using a 2 : 1
stoichiometric ratio led to the formation of complexes 11 and
12, respectively. By interaction of AgNO3 with CP3, PP3 and
NP3 in 3 :1 ratio, all three complexes Ag3(CP3)(NO3)3,28
Ag3(PP3)(NO3)3 (13) and Ag3(NP3)(NO3)3 (14) can be pre-
pared. However the complexes Ag4L(NO3)4 were not achieved
by reaction of PP3 or NP3 with AgNO3 in 1 : 4 ratio. While
Scheme 2 Structural equilibrium proposed for [Ag2(PP3)2](NO3)2 (5)
Au() forms complexes, Au3(CP3)X3,28 Au4(PP3)X4 and Au3-
37
in solution.
(NP3)X3 38 (X = Cl, Br, I), the reaction between AgCl and CP3,
PP3 or NP3 in 3 : 1 and even 4 : 1 ratios led to the formation of
the corresponding 2 : 1 adducts. Likewise all attempts to pre-
pare Ag3(CP3)X3 (X = Br, I) complexes by addition of AgX to
the 2 : 1 adducts were unsuccessful.
while in the 31P-{1H} NMR spectrum of 5, the resonances at
δ Ϫ4.7 and 8.0 are assignable to an uncoordinated and bridging
P, respectively, of the ligands, the resonances at δ Ϫ0.2 and 15.2
can be assigned to the two terminal and the apical coordinated
P respectively of PP3. A similar behaviour of PP3, although
without exchange processes was found in its chlorocomplex
with gold() which exists as a dinuclear ionic compound [Au2-
All complexes were obtained in acceptable yields, the highest
values being for PP3 and NP3 derivatives.
Solution studies
37
(PP3)2]Cl2 both in solution and the solid state, with four-
1 : 1 Complexes. Fig. 1 shows the 31P-{1H} NMR spectra for
complexes Ag(CP3)Cl (1), Ag(PP3)Cl (4), [Ag2(PP3)2](NO3)2 (5),
Ag(NP3)Cl (6), Ag(NP3)(NO3) (7)26 and Ag(CP3)(NO3) (*).28
Complexes Ag(CP3)Cl (1) and Ag(PP3)Cl (4) are fluxional at
room temperature and only broad resonances are observed
which can be attributed to exchange processes involving the
phosphine ligands. For complex Ag(PP3)Cl (4) this broad reson-
ance undergoes splitting into three broad doublets when the
spectrum is recorded in CD2Cl2 at 233 K obtaining an “aver-
age” 1J(AgP) coupling to the two silver isotopes (107Ag, 51.82%
and 109Ag, 48.18%) of ca. 400 Hz (Table 1) characteristic of
silver bound to three 31P atoms.39 Likewise the 1J(AgP) values at
room temperature for Ag(NP3)Cl (6) and Ag(NP3)(NO3) (7) of
277/318 and 344 Hz, respectively, are indicative of a tridentate
chelating mode of coordination through the P atoms for NP3.
The doublet of doublets at δ 7.0 for complex Ag(CP3)(NO3)28
shows 1J(107/109Ag31P) of 487/558 Hz corresponding to Ag()
coordinated to two 31P atoms and suggesting a bidentate chelat-
coordinate Au(). The potential argentophilicity in the disilver
complex 5 could generate a luminescent behaviour40b that will
be investigated subsequently.
On the other hand, while the DMF solutions of 1 : 1 com-
plexes Ag(CP3)X (1–3), Ag(NP3)X (6) and Ag(NP3)(NO3) (7)
behave as non conductors41 in agreement with the presence of
mononuclear compounds, the solutions of Ag(PP3)Cl (4) and
[Ag2(PP3)2](NO3)2 (5) behave as 1 : 1 and 2 : 1 electrolytes,
respectively. The conductivity measurement of 5 in a less
coordinating solvent as CH3CN (273 ohmϪ1 m2 molϪ1 for 10Ϫ3
M solutions) is also in accordance with a behaviour as a 2 : 1
eletrolyte. Furthermore, the presence of the positive ion
[Ag2(PP3)2]2ϩ at m/z 779 as the most intense peak (100%
abundance) in the electron spray mass spectrum (ESMS) of
complex 5 besides the existence of fragments Ag2(PP3)(PP2)
(30% abundance) in its FAB mass spectrum, support a typical
behaviour of a dinuclear and ionic species as described in
Scheme 2. No fragments of higher mass than Ag(PP3) were
J. Chem. Soc., Dalton Trans., 2002, 1110–1118
1113

View Article Online
Fig. 1 31P-{1H} NMR spectra at room temperature for complexes Ag(CP3)Cl (1), Ag(PP3)Cl (4), Ag(NP3)Cl (6), Ag(NP3)(NO3) (7),
Ag(CP3)(NO3)28 (*) (CDCl3) and [Ag2(PP3)2](NO3)2 (5) (CD2Cl2).
Fig. 2 109Ag NMR spectrum for [Ag2(PP3)2](NO3)2 (5) in CD2Cl2:
a) 1J(AgP) = 170 Hz; b) 1J(AgP) = 270 Hz.
found in the FAB mass spectrum of 4 and the conductor
behaviour of the potential mononuclear compound in DMF
solution, is presumably due to some exchange processes of the
chloro atom coexisting as ligand and counter ion in this solvent
and/or to a total replacement of chloride by solvent molecules.
However, on the basis of the 31P-{1H} NMR data at 233 K in
Fig. 3 Proposed structures in solution for Ag(CP3)X [X = Cl (1),
CD2Cl2 (Table 1) the existence in solution of 4 as [Ag2(PP3)2-
Cl]Cl, should not be excluded. The dynamic behaviour of
the potential monocationic complex could be parallel to
that shown in Scheme 2, containing now AgP3 and AgP3Cl
environments.
From the solution studies of 1 : 1 complexes we conclude that
while for halide compounds [Ag(CP3)X (1–3), Ag(NP3)Cl (6)] a
similar coordination mode of the phosphine in solution can be
proposed (Fig. 3), for the nitrate derivatives Ag(CP3)(NO3),28
[Ag2(PP3)2](NO3)2 (5) and Ag(NP3)(NO3) (7), the structures are
strongly dependent on the tripodal ligand used. Only the tri-
podal ligand PP3 involves the apical atom in coordination to
silver() (Scheme 2, Fig. 3).
Br (2), I (3)], Ag(NP3)X [X = Cl (6), NO3 (7)], Ag(CP3)(NO3) (*),
Ag3(PP3)(NO3)3 (13) and Ag3(CP3)(NO3)3 (**).
shown in Fig. 3 can be proposed for complex 13. This structure
28
differs from that one found in solution for Ag3(CP3)(NO3)3
where the 1J(107/109AgP) values of 694/801 Hz are consistent
with each Ag being coordinated to only one P, and the nitrate
acting as monodentate ligand. The non-coordinating C atom in
apical position of CP3 generates only linear Ag() environments.
1
Although J(AgP) coupling constants values were not avail-
able from the 31P-{1H} NMR spectrum of the complex
Ag2(PP3)(NO3)2 (11) in CDCl3 (Table 1), on the basis of the
presence of three resonances at δ 49.4, 12.6 and 10.0 with inte-
gration ratios 1 : 1 : 2, respectively, a structure containing linear
and tetrahedral Ag() and participation of nitrate anions as
ligands can be proposed. The position of the broad signal at
δ 49.4 is characteristic of oxidized apical phosphorus of PP3.
The complexes Ag2(CP3)I2 (10) and Ag2(PP3)(NO3)2 (11)
behave as non conductors in DMF solutions (12.1 and 9.7
ohmϪ1 cm2 molϪ1 respectively). However, the nitrate derivatives
with NP3, Ag2(NP3)(NO3)2 (12) and Ag3(NP3)(NO3)3 (14)
behave as 2 : 1 (148.8 ohmϪ1 cm2 molϪ1) and 3 : 1 (182.3
2 : 1 and 3 : 1 Complexes. These complexes and particularly
those derived from silver() halides showed low solubilities in
the common organic solvents.
Except for Ag2(PP3)(NO3)2 (11) all 2 : 1 and 3 : 1 complexes
(Scheme 1) show a single resonance in their 31P-{1H} NMR
spectra at room temperature in agreement with a fluxional
behaviour characteristic of the coordination chemistry of silver.
For complex Ag3(PP3)(NO3)3 (13) the single broad signal at
δ 7.4 in (DMF ϩ CDCl3) is an unresolved pair of doublets. At
253 K the signal splits (Table 1) into two overlapped broad
doublets at δ 7.6 and 10.4, from which the 1J(AgP) values of 512
and 752 Hz are indicative of Ag() bound to two and one 31P
atoms respectively. On the basis of these data a structure as
ohmϪ1cm2molϪ1
) electrolytes, respectively, because of the
replacement of nitrate by solvent molecules, in good agreement
with the behaviour previously found for Ag3(CP3)(NO3)3 in the
same solvent.28 These similarities between nitrate derivatives
of CP3 and NP3 lead to suppose the exclusion of the apical
1114
J. Chem. Soc., Dalton Trans., 2002, 1110–1118

View Article Online
nitrogen atom in the coordination to silver(). An intermediate
behaviour between a 2 : 1 and 1 : 1 electrolyte was observed for
complex Ag3(PP3)(NO3)3 (13), presumably due to the partici-
pation of the apical phosphorus atom in the coordination
about silver() as proposed in Fig. 3. The presence of Ag2LX
fragments for all these 2 : 1 and 3 : 1 complexes and Ag3LX2
(14) in the FAB mass spectra confirm the existence of polynu-
clear systems.
This compound was crystallized as colourless rods from a mix-
ture of CH2Cl2 and CH3CN. A summary of crystal structure
parameters, data collection and refinement is given in Table 2.
The ORTEP diagram with numbering scheme is shown in Fig. 4
Conversion of stoichiometries
The reactions of Ag2(NP3)(NO3)2 (12) and Ag3(NP3)(NO3)3 (14)
with NP3 and of Ag3(PP3)(NO3)3 (13) with PP3 were followed
by 31P-{1H} NMR and the results listed in Table 1 show that
the conversion of stoichiometries and structures to those of
complexes prepared in 1 : 1 metal : ligand ratio took place in
solution (eqn. (1))
(1)
The single resonance observed in the 31P-{1H} NMR spectra
for complexes Ag2(NP3)(NO3)2 (12) (δ Ϫ2.9 in CDCl3) and
Ag3(NP3)(NO3)3 (14) (δ 0.6 in DMSO-d6) shifts and converts
into the doublets at δ Ϫ8.5 [1J(AgP) = 343 Hz] and Ϫ4.1
[1J(AgP) = 336 Hz] by addition of 1 and 2 molar equivalents of
NP3, respectively, with formation of complex Ag(NP3)(NO3)
(7). Subsequent additions of NP3 produce a decrease in 1J(AgP)
(243 Hz when 4.0 molar equivalents of NP3 were added to
complex 12, Table 1) indicating the formation of AgP4 species.
Likewise, the broad resonance at δ 7.4 in CDCl3/DMF (r.t.) for
complex Ag3(PP3)(NO3)3 (13) converts by addition of 2 molar
equiv. of PP3 into two doublets at δ Ϫ3.1 and 12.4 assigned to
complex [Ag2(PP3)2](NO3)2 (5) (Table 1). After addition of the
third equivalent of PP3 signals attributed to free ligand (δ Ϫ14.9
and Ϫ10.7) together with those belonging to the complex 5
[δ Ϫ2.6 and 12.4; 1J(AgP) = 191 and 442 Hz respectively]
were observed.
The structural changes found by addition of ligand to the
polynuclear nitrate complexes (2 : 1 and 3 : 1) can be associated
in all cases to ring-closure processes. Similar ring-closure reac-
tions were previously detected when the linear triphosphine,
Ph2P(CH2)2PPh(CH2)2PPh2 (P3) was added to polynuclear ionic
[Pt(P3)Cl][Pt2(P3)Cl5] and neutral, Pt3(P3)2Cl6 complexes of
platinum() with formation of [Pt(P3)Cl]Cl.42
Fig. 4 ORTEP diagram for the crystal structure of Ag(NP3)Cl (6).
and selected bond lengths and angles are given in Table 3. This
compound crystallises in space group P1 and consists of
monomeric, neutral Ag(NP3)Cl units with the silver atom in a
slightly distorted tetrahedral environment bound to all three P
atoms of NP3 and the Cl atom. The N atom does not appear to
participate in the coordination and it is located at a distance of
3.126 Å from the metal. This distance is greater than that found
for Ag(NP3)(NO3) (7)26 [2.55(1) Å]. The Ag–Cl and Ag–P bond
distances are in agreement with the same distances found for
other silver() complexes with tetrahedral AgP3Cl environments
such as Ag(PPh3)3Cl43 or Ag(TP)Cl44 (TP = bis[2-(diphenyl-
phosphino)phenyl]phenylphosphine). The Ag() atom is found
to be out of the P3 plane on the side of the chloro ligand giving
rise to P–Ag–P angles very close to those of the tetrahedral
geometry. The distortion from this geometry is higher for
complex Ag(NP3)(NO3) (7) and particularly higher for com-
plex Ag(CP3)I (3).24 While the packing diagram for 3 and 7
involves four molecules in the unit cell, only one is involved for
complex 6.
From these crystallographic studies and by comparison with
solution studies we can conclude that complex 6 together with
complexes 3 and 7 have the same structural behaviour in solu-
tion and solid state.
The titrations with CP3 of complexes 8–10 to form the
corresponding 1 : 1 complexes were also monitored by 31P-{1H}
NMR. However, the appearance of broad resonances did not
allow to obtain useful information.
2 : 1 and 3 : 1 Complexes. The position and number of bands
assigned in the far IR spectra to ν(Ag–X) for complexes
Ag2(CP3)X2 (8–10) indicate that X is coordinating to silver()
in a bridging mode.45 Because of the splitting of νa(N–O) in
the IR spectra of the nitrate derivatives, Ag2(PP3)(NO3)2 (11),
Ag2(NP3)(NO3)2 (12), Ag3(PP3)(NO3)3 (13) and Ag3(NP3)-
(NO3)3 (14), the structures seem to involve the participation
of nitrate groups as coordinating ligands in accordance with
structures proposed in solution.
The very short structural information obtained for halide
complexes Ag2(CP3)X2 (8–10) in solution found compensation
in solid state with the formation of crystals suitable for X-ray
crystallography studies.
Solid state studies
1 : 1 Complexes. The single silver-halogen vibrational fre-
quency found in the far IR spectra of halide complexes 1–4 and
6 is consistent with the presence of terminal Ag–X bonds.6 The
splitting of νa(N–O) observed for complex Ag(NP3)(NO3) (7) is
in accordance with results obtained from X-ray crystallography
studies26 revealing the presence of coordinated nitrate. How-
ever the only frequency without splitting (1383 cmϪ1) found for
complex Ag2(PP3)2(NO3)2 (5) assignable to νa(N–O) suggests
the presence of ionic nitrate39 in the solid state.
The best way to confirm the geometry of these complexes in
solid state is by X-ray diffraction studies. The crystal structures
of Ag(CP3)I (3) and Ag(NP3)(NO3) (7) were previously
reported by Camalli and Caruso24 and Fackler, Jr. and co-
workers26 respectively, and they consist of mononuclear com-
pounds with CP3 and NP3 acting as tridentate chelating ligands.
In this work we report the crystal structure of Ag(NP3)Cl (6).
From solutions of Ag(CP3)Cl (1) and Ag(CP3)Br (2) in DMF
colourless plates and prisms of 8ؒ2DMF and 9, respectively,
were obtained. Compound 10 crystallized from DMSO solu-
tions in colourless prisms as the solvate 10ؒ3DMSO. The crystal
structures of 8ؒ2DMF, 9, and 10ؒ3DMSO are monoclinic, all
with space group P21/c, and their crystallographic data are
given in Table 2. In all three complexes the structures consist of
J. Chem. Soc., Dalton Trans., 2002, 1110–1118
1115

View Article Online
Table 2 Crystallographic data for 6, 8ؒ2DMF, 9 and 10ؒ3DMSO
Complex
6
8ؒ2DMF
9
10ؒ3DMSO
Empirical formula
Formula weight
C42H42NP3ClAg
797.00
C47H53Cl2P3Ag2N2O2
1057.46
C41H39Br2P3Ag2
1000.19
C47H57I2P3Ag2S3O3
1328.56
Temperature/K
Wavelength/Å
293(2)
0.71073
293(2)
0.71073
293(2)
0.71073
293(2)
0.71073
Crystal size/mm
Colour/habit
Crystal system
Space group
0.58 × 0.23 × 0.19
Colourless/rod
Triclinic
0.22 × 0.22 × 0.12
Colourless/plate
Monoclinic
P21/c
0.39 × 0.30 × 0.18
Colourless/prism
Monoclinic
P21/c
0.34 × 0.17 × 0.07
Colourless/prism
Monoclinic
P21/c
P1
a/Å
b/Å
c/Å
α/Њ
8.895(4)
18.060(3)
14.866(3)
18.468(4)
90
19.486(3)
9.7523(13)
20.388(3)
13.926(4)
19.209(5)
19.642(5)
90
10.339(4)
10.809(4)
74.50(2)
90
β/Њ
80.92(2)
79.66(2)
936.0(6)
1
1.414
0.769
105.862(4)
90
4769.5(16)
4
1.473
1.072
95.638(4)
90
3855.5(9)
4
1.723
3.242
98.190(5)
90
5201(2)
4
1.697
2.190
γ/Њ
V/Å3
Z
Dc/Mg mϪ3
µ/mmϪ1
F(000)
410
2152
1976
2624
θ range for data collection/Њ
Index ranges
2.88–25.01
Ϫ10 ≤ h ≤ 10
Ϫ12 ≤ k ≤ 12
Ϫ12 ≤ l ≤ 12
8884
1.17–27.08
Ϫ23 ≤ h ≤ 15
Ϫ18 ≤ k ≤ 18
Ϫ21 ≤ l ≤ 22
28519
9827 [Rint = 0.1558]
0.8821, 0.7983
9827/0/479
0.811
1.05–30.54
Ϫ27 ≤ h ≤ 25
Ϫ12 ≤ k ≤ 13
Ϫ28 ≤ l ≤ 29
47731
11712 [Rint = 0.0720]
0.5930, 0.3645
11712/0/434
0.887
1.48–23.35
Ϫ15 ≤ h ≤ 10
Ϫ21 ≤ k ≤ 21
Ϫ21 ≤ l ≤ 21
23626
7508 [Rint = 0.1791]
0.8618, 0.5230
7508/0/481
0.888
Reflections collected
Independent reflections
Max., min. transmission
Data/restraints/parameters
Goodness of fit on F 2
Final R indices
6564 [Rint = 0.0102]
6564/3/433
1.025
R1 = 0.0174, wR2 = 0.0454
R1 = 0.0178, wR2 = 0.0456
0.368 and Ϫ0.606
R1 = 0.0524, wR2 = 0.0882
R1 = 0.2436, wR2 = 0.1311
0.587 and Ϫ0.686
R1 = 0.0345, wR2 = 0.0665
R1 = 0.1232, wR2 = 0.0949
0.626 and Ϫ0.639
R1 = 0.0889, wR2 = 0.2137
R1 = 0.2818, wR2 = 0.3008
2.256 and Ϫ1.891
R indices (all data)
Largest diff. peak and
hole (e ÅϪ3
)
Table 3 Selected bond lengths (Å) and angles (Њ) for 6
Table 4 Selected interatomic distances (Å) and bond angles (Њ) and
important noncovalent contacts for 8ؒ2DMF, 9 and 10ؒ3DMSO
Ag(1)–Cl(1)
Ag(1)–P(2)
2.593(1)
2.516(1)
Ag(1)–P(1)
Ag(1)–P(3)
2.517(1)
2.549(1)
8ؒ2DMF
9
10ؒ3DMSO
P(2)–Ag(1)–P(1) 105.63(3)
P(1)–Ag(1)–P(3) 108.16(3)
P(2)–Ag(1)–P(3) 108.66(3)
P(3)–Ag(1)–Cl(1) 108.03(3)
P(1)–Ag(1)–Cl(1) 109.32(3)
P(2)–Ag(1)–Cl(1) 116.76(3)
Ag(1)–P(1)
Ag(2)–P(3)
Ag(2)–P(2)
Ag(1)–X(2)#2
Ag(1)–X(1)#2
Ag(2)–X(1)
Ag(2)–X(2)
2.364(3)
2.463(2)
2.502(3)
2.469(3)
2.498(3)
2.620(3)
2.642(3)
2.392(11)
2.498(11)
2.484(11)
2.576(7)
2.666(6)
2.762(6)
2.727(6)
2.415(6)
2.504(7)
2.590(8)
2.774(3)
2.793(3)
2.888(3)
2.880(3)
Ag(1) ؒ ؒ ؒ ؒN(1)
3.126
P(3)–Ag(2)–P(2)
P(1)–Ag(1)–X(1)#2
P(1)–Ag(1)–X(2)#2
P(3)–Ag(2)–X(1)
P(2)–Ag(2)–X(2)
P(2)–Ag(2)–X(1)
P(3)–Ag(2)–X(2)
X(2)#2–Ag(1)–X(1)#2
X(1)–Ag(2)–X(2)
97.77(8)
127.15(9)
136.80(9)
114.24(8)
115.37(9)
117.07(9)
126.05(8)
94.75(9)
97.82(4)
123.41(3)
139.42(3)
126.91(3)
114.76(3)
111.78(3)
115.99(3)
96.36(2)
95.50(2)
130.73(18)
129.45(19)
118.12(18)
116.34(19)
119.07(19)
117.17(18)
97.03(9)
87.96(8)
90.78(19)
92.60(8)
Ag(2) ؒ ؒ ؒ Ag(1)#1
3.385(12)
3.321(6)
3.391(3)
phosphorus atom deviating from the plane by 0.047 (Cl), 0.039
(Br) and 0.079 (I) Å with the sum of the angles around the silver
atom not differing much from 360Њ [358.7Њ (Cl), 359.2Њ (Br),
357.2Њ (I)].
In general, the decrease in the halogen electronegativity leads
to an increase in the Ag–P bond lengths. The Ag–P bond
lengths in complex Ag(CP3)I (3) [2.510(5), 2.527(6) and 2.555(5)
Å] are greater than Ag(1)–P(1) [2.415(6) Å] and Ag(2)–P(3)
[2.504(7) Å] and lower than Ag(2)–P(2) [2.590(8) Å] distances in
complex Ag2(CP3)I2 (10).
The Ag(1) also shows shorter Ag–X bond distances than
Ag(2) and, as expected, both Ag(1)–I and Ag(2)–I distances
corresponding to bridging bonds are longer than Ag–I bond
lengths in complex Ag(CP3)I (3) containing only terminal Ag–I
bonds.
Fig. 5 ORTEP view of the asymmetric unit for complex 8.
repeating asymmetric units, AgPCP2AgX2 (Fig. 5 for X = Cl)
giving rise to infinite chains where three- [Ag(1)] and four-
coordinate silver() [Ag(2)] coexist (Fig. 6). Table 4 shows
selected interatomic distances (Å) and bond angles (Њ). The
shortest Ag–P bond distances are found in the three-coordinate
silver environment PAgX2 which is almost planar with the
1116
J. Chem. Soc., Dalton Trans., 2002, 1110–1118

View Article Online
Fig. 6 Fragment of an infinite chain for 8, 9 and 10. Phenyl rings are omitted for clarity.
The distorted tetrahedral environment in the P2AgX2
silver coordination sphere is evident from the P–Ag–P and
X–Ag–X angles which are significantly lower than 109Њ or
from the P–Ag–X angles which are higher than 109Њ in all three
cases. Similar trends in deviations from the tetrahedral geom-
etry were observed for P–Ag–P and P–Ag–X angles in complex
Ag(CP3)I (3).
There is only a weak Ag(1) ؒ ؒ ؒ Ag(2)# interaction [3.385(12),
X = Cl (8); 3.321(6), X = Br (9); 3.391(3), X = I (10)] between
three- and four-coordinate silver atoms of two different asym-
metric units and bridged by two halogen atoms. The predictions
by IR about the presence of halogens bridging two silver
centres were now confirmed.
Crystals of Ag2(CP3)Cl2 (8) and Ag2(CP3)I2 (10) are made up
of infinite zigzag chains which involve monomer units related
within the chains by glide planes (8) or screw axes along the
chains (10) and with the solvent molecules occupying the voids
formed between them. There are two chains running through
the unit cell along the c and b axis for 8 and 10, respectively
(Figs. 6, 7). The number of asymmetric units per chain along the
propagation axis for 8 and 10 is two. However crystals of com-
plex Ag2(CP3)Br2 (9) are made up of infinite linear chains with
the monomer units related solely by translation. There are now
four chains running through the unit cell (Fig. 7) with only one
asymmetric unit per chain along the b axis. The high calculated
density for 9 (Dc = 1.723 Mg mϪ3) is indicative that the cavities
of the tunnels generated along the propagation axis are not
large enough to accommodate solvent molecules.
Fig. 7 Propagation of four linear chains for complex 9 and two zigzag
chains for complex 10 running along the b axis of the unit cell. Phenyl
rings are omitted for clarity.
chains held together by chain–chain (9) and chain–solvent–
chain van der Waals interactions (8, 10).46 This contrasts with
the double and higher order helices in coordination polymers
where the strands of the helix are independent infinite chains,
connected by noncovalent forces, quite analogous to the situ-
ation in DNA.21 Efficient π-stacking interactions involving
phenyl rings of CP3 between neighbouring chains probably
strongly support the cohesion of the crystals. The crystal struc-
tures of 8, 9 and 10 constitute the first examples of infinite
chains found for metal complexes of tripodal polyphosphines
as CP3, PP3 or NP3. The structural characteristics of these
The shortest Ag ؒ ؒ ؒ Ag distances between chains involving
three- and four-coordinate silver() centres are 11.697 Å for
complex 9 and 16.586 and 17.229 Å for complexes 8 and 10,
respectively.
The neutral polymeric chains found in complexes 8–10 are
not connected by H-bonding. They are independent infinite
J. Chem. Soc., Dalton Trans., 2002, 1110–1118
1117

View Article Online
11 P. G. Jones, Acta Crystallogr., Sect. C., 1993, 49, 1148.
neutral polymeric chains in the solid state can explain the
unsuccessful attempts to prepare the corresponding 3 : 1
adducts.
12 G. A. Bowmaker, Effendy, P. J. Harvey, P. C. Healy, B. W. Skelton
and A. H. White, J. Chem. Soc., Dalton Trans., 1996, 2449.
13 M. Camalli and F. Caruso, Inorg. Chim. Acta, 1988, 144, 205.
14 A. Del Zotto, P. Di Bernardo, M. Tolazzi, G. Tomat and P.
Zanonato, J. Chem. Soc., Dalton Trans., 1993, 3009.
Conclusions
15 D. Arffandi, S. J. Berners-Price, Effendy, P. J. Harvey, P. C. Healy,
B. E. Ruch and A. H. White, J. Chem. Soc., Dalton Trans., 1997,
1411.
16 S.-M. Kuang, L.-M. Zhang, Z.-Z. Zhang, B. M. Wu and T. C. W.
Mak, Inorg. Chim. Acta, 1999, 284, 278.
17 Z.-M. Che, H.-K. Yip, V. W.-W. Yam, P.-Y. Cheung, T.-F. Lai,
S.-J. Shieh and S.-M. Peng, J. Chem. Soc., Dalton Trans., 1992, 427.
18 A. L. Airey, G. F. Swiegens, A. C. Willis and S. B. Wild, Inorg.
Chem., 1997, 36, 1588.
19 S. Sailaja and M. V. Rajasekharan, Inorg. Chem., 2000, 39, 4586.
20 C.-T. Chen and K. S. Suslick, Coord. Chem. Rev., 1993, 128, 293.
21 O. Kahn and C. J. Martínez, Science, 1998, 279, 44.
22 M. Bertelli, L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi,
J. Mater. Chem., 1997, 7, 1271.
23 J. F. Corrigan, D. Fenske and W. P. Power, Angew. Chem., Int. Ed.
Engl., 1997, 36, 1176.
24 M. Camalli and F. Caruso, Inorg. Chim. Acta, 1990, 169, 189.
25 S. L. James, D. M. P. Mingos, A. J. P. White and D. J. Williams,
Chem. Commun., 1998, 2323.
26 M. N. I. Khan, R. J. Staples, C. King, J. P. Fackler Jr. and R. E. P.
Winpenny, Inorg. Chem., 1993, 32, 5800.
27 M. Barrow, H. B. Bürgi, M. Camalli, F. Caruso, E. Fisher,
L. M. Venanzi and L. Zambonelli, Inorg. Chem., 1983, 22, 2356.
28 P. Sevillano, M. E. García, A. Habtemaniam, S. Parsons and
P. J. Sadler, Metal-Based Drugs, 1999, 6, 211.
While the 1 : 1 complexes of silver() halides with pendant tri-
phosphines as CP3 and NP3 show the same coordination mode
of the ligand through the 3 P atoms, the structures in solution
of the 1 : 1 nitrate derivatives are strongly dependent on the
phosphineused, revealingAgP2, AgP3 ϩAgP4 andAgP3 environ-
ments for CP3, PP3 and NP3 complexes, respectively, in consist-
ence with the formation of a dinuclear cationic system in the
case of PP3. The 2 : 1 and 3 : 1 complexes of silver() nitrate with
these triphosphines involve the participation of nitrate anion as
coordinating ligand and convert into the corresponding 1 : 1
complex by addition of phosphine. The crystal structures of the
2 : 1 adducts of silver() halides with CP3, Ag2(CP3)X2 (X = Cl,
Br, I), consist of two infinite zigzag (X = Cl, I) or four linear
chains (X = Br) which run along the unit cell. Silver() is three-
and four-coordinate and bridged by two halogen atoms. The
zigzag arrangement (X = Cl, I) generates cavities with appropri-
ate size to accommodate solvent molecules. Further additions
of AgX to these 2 : 1 adducts did not lead to the formation of
Ag3(CP3)X3 complexes.
29 M. M. Taqui Khan and E. Rama Rao, Polyhedron, 1988, 7, 29.
30 L. Sacconi and I. Bertini, J. Am. Chem. Soc., 1968, 90, 5443.
31 Bruker, SMART and SAINT, Area Detector Control and
Integration Software, Bruker Analytical X-ray Instruments Inc.,
Madison, WI, USA, 1997.
32 G. M. Sheldrick, SADABS, Program for Empirical Absorption
Correction of Area Detector Data, University of Göttingen,
Germany, 1997.
Acknowledgements
We thank Xunta de Galicia for financial support. Crystallo-
graphic data for complex 6 were measured at the University of
Edinburgh, UK, and intensity measurements of crystals for
complexes 8, 9 and 10 were performed at the Unidade de Raios
X, RIAIDT, University of Santiago de Compostela, Spain.
33 G. M. Sheldrick, Acta Crystallogr., Sect. A, 1990, 46, 467.
34 G. M. Sheldrick, SHELXL-97, Program for the Refinement of
Crystal Structures, University of Göttingen, Germany, 1997.
35 International Tables for X-ray Crystallography, Kluwer Academic
Publishers, Dordrecht, The Netherlands, 1995, vol. C.
36 L. J. Farrugia, J. Appl. Crystallogr., 1997, 30, 565.
37 A. L. Balch and E. Y. Fung, Inorg. Chem., 1990, 29, 4764.
38 J. Zank, A. Schier and H. Schmidbaur, Z. Naturforsch., Teil B, 1997,
52, 1471.
39 P. F. Barron, J. C. Dyason, P. C. Healy, L. M. Engelhardt, B. W.
Skelton and A. H. White, J. Chem. Soc., Dalton Trans., 1986, 1965.
40 (a) K. Zangger and I. M. Armitage, Metal-Based Drugs, 1999, 6,
239; (b) C.-M. Che, M. C. Tse, M. C. W. Chan, K.-K. Cheung, D. L.
Phillips and K.-H. Leung, J. Am. Chem. Soc., 2000, 122, 2464.
41 W. J. Geary, Coord. Chem. Rev., 1971, 7, 81.
References
1 (a) C. A. Crawford, E. F. Day, W. E. Streib, J. C. Huffman and
G. Christou, Polyhedron, 1994, 13, 2933; (b) M.-L. Tong,
X.-M. Chen, B.-H. Ye and S. W. Ng, Inorg. Chem., 1998, 37,
5278.
2 P. Di Bernardo, G. Dolcetti, R. Portanova, M. Tolazzi, G. Tomat
and P. Zanonato, Inorg. Chem., 1990, 29, 2859.
3 M. R. Churchill, J. Donahue and F. J. Rotella, Inorg. Chem., 1976,
15, 2752.
4 B. K. Teo and J. C. Calabrese, Inorg. Chem., 1976, 15, 2467.
5 M. Bardají, O. Crespo, A. Laguna and A. K. Fischer, Inorg. Chim.
Acta, 2000, 304, 7.
6 G. A. Bowmaker, Effendy, P. J. Harvey, P. C. Helay, B. W. Skelton
and A. H. White, J. Chem. Soc., Dalton Trans., 1996, 2459.
7 E. R. T. Tiekink, Coord. Chem., 1988, 17, 239.
8 A. Baiada, F. H. Jardine and R. D. Willet, Inorg. Chem., 1990, 29,
3042.
42 M. I. García-Seijo, A. Castiñeiras, B. Mahieu, L. Jánosi, Z. Berente,
L. Kóllar and M. E. García-Fernández, Polyhedron, 2001, 20, 855.
43 A. Cassel, Acta Crystallogr., Sect. B, 1981, 37, 229.
44 J. Zank, A. Schier and H. Schmidbaur, J. Chem. Soc., Dalton Trans.,
1999, 415.
9 G. Wulfsberg, D. Jackson, W. IIsley, S. Dou, A. Weiss and
J. Gagliardi Jr., Z. Naturforsch., Teil A, 1992, 47, 75.
10 G. A. Bowmaker, Effendy, J. V. Hanna, P. C. Healy, B. W. Skelton
and A. H. White, J. Chem. Soc., Dalton Trans., 1993, 1387.
45 S. Attar, N. W. Alcock, G. A. Bowmaker, J. S. Frye, W. H. Bearden
and J. H. Nelson, Inorg. Chem., 1991, 30, 4166.
46 O. Mamula, A. V. Zelewsky, T. Bark and G. Bernardinelli, Angew.
Chem., Int. Ed., 1999, 38, 2945.
1118
J. Chem. Soc., Dalton Trans., 2002, 1110–1118