Transition metal chemistry of cyclodiphosphanes containing phosphine and amide-phosphine functionalities: Formation of a stable dipalladium(II) complex containing a Pd-P σ-bond.

Article abstract of DOI:10.1039/c0dt00614a

Cyclodiphosphazanes containing phosphine or phosphine plus amide functionalities {(^tBuNP(OC₆H₄PPh ₂-o)}₂ (3), {^tBuNP(OCH₂CH ₂PPh₂)}₂ (4), {^tBuHN( ^tBuNP)₂OC₆H₄PPh₂-o} (5), and {^tBuHN(^tBuNP)₂OCH₂CH ₂PPh₂} (6) were synthesized by reacting cis-{ ^tBuNPCl}₂ (1) and cis-[^tBuHN( ^tBuNP)₂Cl] (2) with corresponding phosphine substituted nucleophiles. The reactions of 3 and 5 with excess of elemental sulfur or selenium produce the corresponding tetra and trichalcogenides, {( ^tBuNP(E)(OC₆H₄P(E)Ph₂-o)} ₂ (7, E = S; 8, E = Se) and {^tBuHN(^tBuNP) ₂OC₆H₄P(E)Ph₂-o} (9, E = S; 10, E = Se), respectively, in quantitative yields. The reactions between 3 and [Rh(COD)Cl]₂ or [M(COD)Cl]₂ (M = Pd or Pt) afford bischelated complexes [Rh(CO)Cl{^tBuNP(OC₆H ₄PPh₂-o)}]₂ (11), and [MCl₂{ ^tBuNP(OC₆H₄PPh₂-o)}]₂ (12, M = Pd; 13, M = Pt) in good yield. The 1:2 reaction between 3 and [PdCl(η³-C₃H₅)]₂ in dichloromethane resulted initially in the formation of a tripalladium complex of the type [Pd₃Cl₄(η³-C₃H ₅)₂{^tBuNPOC₆H₄PPh ₂}₂] (14a) which readily reacts with moisture to form an interesting binuclear complex, [Cl₂Pd{μ-(PPh₂C ₆H₄OP(μ-^tBuN)₂P(O)}(μ-Cl) Pd(OC₆H₄PPh₂)] (14b). One of the palladium(ii) atoms forms a simple six-membered chelate ring, whereas the other palladium(ii) atom facilitates the moisture assisted cleavage of one of the endocyclic P-O bonds followed by the oxidation of P(iii) to P(v) thus forming a Pd-P σ-bond. The broken ortho-phosphine substituted phenoxide ion forms a five-membered palladacycle with the same palladium(ii) atom. Similar reaction of 5 with [PdCl(η³-C₃H₅)]₂ also affords a binuclear complex [{PdCl(η³-C₃H ₅)}^tBuNH{^tBuNP}₂OC₆H ₄PPh₂{PdCl₂}] (15) containing a PdCl ₂ moiety which forms a six-membered chelate ring via ring-phosphorus and PPh₂ moieties on one side and a PdCl(η³-C ₃H₅) fragment coordinating to amide bound phosphorus atom on the other side of the ring. Treatment of 3 with four equivalents of AuCl(SMe₂) produces a tetranuclear complex, [(AuCl)₄{ ^tBuNP(OC₆H₄PPh₂)}₂] (16), whereas a 1:3 reaction between 5 and AuCl(SMe₂) leads to the formation of a trinuclear complex, [^tBuNH{^tBuNP(AuCl)} ₂OC₆H₄P(AuCl)Ph₂] (17). The crystal structures of 3, 5, 9-11 and 13-17 are reported.

Full text of DOI:10.1039/c0dt00614a

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Transition metal chemistry of cyclodiphosphanes containing phosphine and
amide-phosphine functionalities: Formation of a stable dipalladium(II)
complex containing a Pd–P r-bond.†
Maravanji S. Balakrishna,*a Ramalingam Venkateswarana and Joel T. Magueb
Received 7th June 2010, Accepted 2nd August 2010
DOI: 10.1039/c0dt00614a
Cyclodiphosphazanes containing phosphine or phosphine plus amide functionalities
t
t
{(tBuNP(OC6H4PPh2-o)}2 (3), { BuNP(OCH2CH2PPh2)}2 (4), { BuHN(tBuNP)2OC6H4PPh2-o} (5),
and { BuHN(tBuNP)2OCH2CH2PPh2} (6) were synthesized by reacting cis-{ BuNPCl}2 (1) and
cis-[tBuHN(tBuNP)2Cl] (2) with corresponding phosphine substituted nucleophiles. The reactions of 3
and 5 with excess of elemental sulfur or selenium produce the corresponding tetra and trichalcogenides,
t
t
{(tBuNP(E)(OC6H4P(E)Ph2-o)}2 (7, E = S; 8, E = Se) and { BuHN(tBuNP)2OC6H4P(E)Ph2-o} (9, E = S;
t
10, E = Se), respectively, in quantitative yields. The reactions between 3 and [Rh(COD)Cl]2 or
t
[M(COD)Cl]2 (M = Pd or Pt) afford bischelated complexes [Rh(CO)Cl{ BuNP(OC6H4PPh2-o)}]2 (11),
t
and [MCl2{ BuNP(OC6H4PPh2-o)}]2 (12, M = Pd; 13, M = Pt) in good yield. The 1 : 2 reaction between
3
3 and [PdCl(h -C3H5)]2 in dichloromethane resulted initially in the formation of a tripalladium complex
3
t
of the type [Pd3Cl4(h -C3H5)2{ BuNPOC6H4PPh2}2] (14a) which readily reacts with moisture to form
an interesting binuclear complex, [Cl2Pd{m-(PPh2C6H4OP(m-tBuN)2P(O)}(m-Cl)Pd(OC6H4PPh2)] (14b).
One of the palladium(II) atoms forms a simple six-membered chelate ring, whereas the other
palladium(II) atom facilitates the moisture assisted cleavage of one of the endocyclic P–O bonds
followed by the oxidation of P(III) to P(V) thus forming a Pd–P s-bond. The broken ortho-phosphine
substituted phenoxide ion forms a five-membered palladacycle with the same palladium(II)
3
atom. Similar reaction of 5 with [PdCl(h -C3H5)]2 also affords a binuclear complex
3
t
t
[{PdCl(h -C3H5)} BuNH{ BuNP}2OC6H4PPh2{PdCl2}] (15) containing a PdCl2 moiety which
forms a six-membered chelate ring via ring-phosphorus and PPh2 moieties on one side and a
3
PdCl(h -C3H5) fragment coordinating to amide bound phosphorus atom on the other side of the
ring. Treatment of 3 with four equivalents of AuCl(SMe2) produces a tetranuclear complex,
t
[(AuCl)4{ BuNP(OC6H4PPh2)}2] (16), whereas a 1 : 3 reaction between 5 and AuCl(SMe2) leads to the
t
formation of a trinuclear complex, [tBuNH{ BuNP(AuCl)}2OC6H4P(AuCl)Ph2] (17). The crystal
structures of 3, 5, 9–11 and 13–17 are reported.
N, which resulted in the formation of several metallamacrocycles
Introduction
(Rh,5 Cu,6 Ag,7 Au8) and, 1D, 2D and 3D coordination polymers
(Cu,9,10 Ag11). As an extension of our interest and for the interest of
others2,3 in cyclodiphosphazane ligand systems, we report in this
paper the first examples of cyclodiphosphazane-derived phosphine
ligands and their transition metal chemistry.
The recent upsurge interest in the chemistry of cyclodiphos-
phazanes or diazadiphosphetidines is due to their utility as
ligands towards both main group and transition elements,1
building blocks in macrocyclic chemistry,2 mechanistic probes
for organic reactions, and catalytic3 and biological applications.4
The coordination behavior of cyclodiphosphazanes is governed
by both steric and electronic attributes which can be read-
ily tuned through phosphorus substituents. Recently we have
explored the rich and versatile transition metal chemistry of
Results and discussion
Ligand synthesis
t
cyclodiphosphazanes of the type { BuNPX}2 (X = OC6H4OMe-
The
bis(phosphine)
derivative
of
cyclodiphosphazane
o, OCH2CH2OMe, OCH2CH2SMe, OCH2CH2NMe2, NC4H8O,
t
{ BuNPOC6H4PPh2-o}2 (3) was obtained in excellent yield
NC4H8NMe, NCONR2) containing donor atoms such as O, S and
t
by the reaction of the chloro-derivative, { BuNPCl}2 (1) with
HOC6H4PPh2-o12 in a 1 : 2 ratio in diethyl ether in the presence
aPhosphorus Laboratory, Department of Chemistry, Indian Institute of
Technology Bombay, Mumbai, 400 076, India, 3480. E-mail: krishna@
chem.iitb.ac.in; Fax: +91 22 2576 7152/2572; Tel: +91 22 2576 7181
of 2 equivalents of Et3N as shown in Scheme 1. Similarly, the
t
ligand { BuNP(OCH2CH2PPh2)}2 (4) was prepared from the
13
corresponding 2-diphenylphosphinoethanol, HOCH2CH2PPh2
bTulane University, New Orleans, Louisiana, 70118
in good yield. The 31P NMR spectrum of 3 consists of two
resonances at 132.0 and -20.4 ppm, which are assigned to the
† CCDC reference numbers 779798–779807. For crystallographic data in
CIF or other electronic format see DOI: 10.1039/c0dt00614a
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Synthesis of transition metal complexes
Compounds 3–6 are potential tetra- and tridentate ligands,
and it would be interesting to explore the coordination be-
havior with various transition metal derivatives. In this sec-
tion the transition metal chemistry of two representative lig-
ands 3 and 5 is described. The equimolar reaction of 3 with
[Rh(CO)2Cl]2 in dichloromethane afforded bischelated complex
t
[Rh(CO)Cl{ BuNP(OC6H4PPh2-o)}]2 (11) as shown in Scheme 3.
The infrared spectrum of 11 shows nCO absorptions at 2033 and
2051 cm-1. The 31P NMR spectrum of complex 11 consists of
the AA¢XX¢ portion of an AA¢XX¢MM¢ spin system A, X = 31P;
M = 103Rh) and exhibits multiplets centered at 136.8 and 9.9 ppm
which are assigned to P2N2 and Ph2P, respectively. The mutual cis-
disposition of P2N2 and CO ligands is expected due to the better
p-acceptor ability of the P2N2 phosphorus atom compared to that
Scheme 1
phosphorus atoms in P2N2 ring and PPh2, respectively. The 31P
NMR spectrum of 4 also shows two resonances at 131.0 and
-15.0 ppm, respectively, for the ring phosphorus atoms and PPh2.
The chloroamido derivative, {(tBuN(H)P(m-tBuN)2PCl} (2) on
treatment with stoichiometric amount of HOC6H4PPh2-o or
HOCH2CH2PPh2 in diethyl ether affords the corresponding het-
erodifunctional derivatives, {(tBuN(H)P(m-tBuN)2P(OC6H4PPh2-
o)} (5) and {(tBuN(H)P(m-tBuN)2P(OCH2CH2PPh2)} (6), respec-
tively, in good yields (Scheme 2). The 31P NMR spectrum of 5
consists of three resonances: two doublets centered at 144.5 and
1
in PPh2. The JRhP couplings to the P2N2 phosphorus and PPh2
atoms are, respectively, 201 and 125 Hz with the former larger
due to the greater s character in the phosphorus lone pair orbital
which stems from the strain imposed by the four-membered ring.
The formulation of compound 11 has been confirmed from the
mass spectrometry, which shows a molecular ion peak at m/z
1028.02 (M–Cl∑CO) and the structure was further confirmed by a
single crystal X-ray diffraction study.
2
116.3 ppm with a JPP coupling of 13.4 Hz and one singlet at
-16.5 ppm. The 31P NMR spectrum of 6 is similar to that of
5 and shows three singlets at 112.3, 92.9 and -25.1 ppm. The
resonance at -25.1 ppm corresponds to the exocyclic phosphine
moiety, whereas the other two chemical shifts are due to the P2N2
ring phosphorus atoms; the high-field shift is assigned to amide
phosphorus in all cases.
Scheme 3
The reactions of 3 with 2 equivalents of [M(COD)Cl2] (M =
Pd, Pt) in dichloromethane yielded the bis-chelate complexes,
t
Scheme 2
[(MCl2)2{ BuNP(OC6H4PPh2-o)}2] (12, M = Pd and 13, M =
Pt). The 31P NMR spectrum of 12 exhibits two characteristic
doublets centered at 98.0 and 10.2 ppm due to the P2N2 and
PPh2 centers, respectively, with a 2JPP coupling of 39 Hz. Similarly,
the phosphorus-31 chemical shift due to the P2N2 center of the
analogous platinum complex 13 appears at 90.0 ppm, whereas the
PPh2 groups resonate at -5.7 ppm with respective 1JPtP couplings
of 5522 and 3151 Hz. The 2JPP coupling is 51.5 Hz.
Treatment of 3 with 4 equivalents of elemental sulfur or
selenium in toluene under refluxing conditions resulted in the
t
formation of the tetrasulfide { BuNP(S)(OC6H4P(S)Ph2)}2 (7)
t
and the tetraselenide { BuNP(Se)(OC6H4P(Se)Ph2)}2 (8) deriva-
tives, respectively. A similar reaction of 5 with 3 equiva-
lents of sulfur or selenium afforded respectively, the trisulfide
{(tBu(H)NP(S)(m-tBuN)2P(S)(OC6H4P(S)Ph2-o)} (9) and trise-
lenide {(tBu(H)NP(Se)(m-tBuN)2P(Se)(OC6H4P(Se)Ph2-o)} (10)
derivatives, in quantitative yields. The 31P NMR spectrum of
tetrasulfide 7 shows two singlets at 38.7 and 38.0 ppm, respectively,
for the P2N2 and PPh2 moieties. The tetraselenide 8 also exhibits
single resonances at 29.1 and 27.5 ppm, and each shows 77Se
3
The 1 : 2 reaction between 3 and [PdCl(h -C3H5)]2 in dichlo-
romethane resulted initially in the formation of a tripalladium
3
t
complex of the type [Pd3Cl4(h -C3H5)2{ BuNPOC6H4PPh2}2]
(14a) as confirmed by spectroscopic data.14 Complex 14a consists
of a PdCl2 moiety coordinated to one of the ring phosphorus and
the adjacent exocyclic PPh2 group to form a six-membered chelate
ring. The other two phosphorus centers coordinate separately to
1
satellites with JSeP couplings of 747 and 996 Hz, respectively.
3
The 31P NMR spectra of analogous derivatives 9 and 10 consist of
three resonances due to the presence of three different phosphorus
environments.
[PdCl(h -C3H5)] fragments as shown in Scheme 4. The 31P NMR
spectrum of 14a consists of four resonances: the PPh2 group in
the chelate ring shows a doublet at 7.2 ppm, whereas the ring
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phosphorus present in the chelate ring appears as a doublet
of doublets at 139.5 ppm due to the coupling with both the
established by single crystal X-ray study. The X-ray quality crystals
were obtained only in the 1 : 2 reaction with unreacted/eliminated
2
2
3
PPh2 and the other ring phosphorus atom. The JPPdP and JPNP
couplings are 12 and 51.6 Hz, respectively. The phosphorus-31
resonance due to the other ring phosphorus atom coordinated
[PdCl(h -C3H5)]2 co-crystallizing along with 14b.15 From the
reaction in Scheme 3 it appears that the reaction of 3 with 2
3
equivalents of [PdCl(h -C3H5)]2 proceeds smoothly to produce
3
3
to [PdCl(h -C3H5)] moiety appears as a doublet at 123.2 ppm
14b which crystallizes with one molecule of [PdCl(h -C3H5)]2 as
3
(2JPNP = 51.6 Hz). The [PdCl(h -C3H5)] bound PPh2 exhibits
evinced by its single crystal X-ray structure determination.
3
a single resonance at 15.5 ppm. Complex 14a was crystallized
from a 1 : 2 mixture of dichloromethane and diethyl ether as
pale yellow crystals (14b) whose composition and spectroscopic
data were found to be different from 14a. It is assumed that
during the crystallization, a trace amount of moisture induces
the cleavage of one of the P–O bonds to form Ph2PC6H4OH and
HOP(m-tBuN)2POC6H4PPh2PdCl2. The latter probably undergoes
tautomerism at the uncoordinated phosphorus center followed by
deprotonation to generate a nucleophile [(PdCl2}Ph2PC6H4OP(m-
tBuN)2P(O)]- which eventually forms a Pd–P s-bond, whereas
the Ph2PC6H4O- fragment forms a metallacycle with the same
palladium as shown in Scheme 4. If the original reaction is
performed in wet solvent complex 14b forms in quantitative yield
although initial formation of 14a occurs as indicated by the in situ
31P NMR spectrum. Surprisingly, the other P–O did not break
during the reaction and complex 14b is found to be stable towards
air and moisture both in the solid state and in solution.
A
similar reaction between
5
and [PdCl(h -C3H5)]2
3
led to the isolation of
a dinuclear complex, [Pd2Cl3(h -
C3H5)tBuNH{ BuNP}2OC6H4PPh2] (15). The structure of com-
plex 15 consists of a six-membered chelate ring containing a
{PdCl2} moiety and involving the phenoxy-bound ring phospho-
rus atom and PPh2 center. The amide-functionalized phosphorus
t
atom binds to a {PdCl(h -C3H5)} moiety. The 31P NMR spectrum
3
of 15 consists of three resonances: the phenoxy bound ring
phosphorus and the PPh2 group present, respectively, a doublet
of doublets at 99.6 and a doublet at -9.5 ppm with 2JPP couplings
of 42.3 and 11.2 Hz. The amido-phosphorus is coupled to the
former (2JPP = 42.3 Hz) and exhibits a doublet at 90.9 ppm. The
mass spectrum of 15 shows a molecular ion peak at m/z 877.93 [M
- Cl]+. The reaction of 3 and 5 with [AuCl(SMe2)], respectively, in
1 : 4 and 1 : 3 molar ratios leads to the formation of tetranuclear
t
and trinuclear complexes, [(AuCl)4{ BuNP(OC6H4PPh2)}]2 (16)
t
and [tBuNH{ BuNP(AuCl)}2OC6H4P(AuCl)Ph2] (17). The 31P
NMR spectrum of 16 shows two resonances at 101.4 and 21.9 ppm,
respectively, for the P2N2 and PPh2 centers. The 31P NMR
spectrum of 17 exhibits three signals which consist of two doublets
centered at 88.9 and 71.0 ppm (2JPP = 8.9 Hz) corresponding to
the phenoxo- and amido-phosphorus atoms and the singlet at
19.1 ppm corresponding to the PPh2 moiety. Further the molecular
structures of 16 and 17 were confirmed by single crystal X-ray
structure determination.
Molecular structures of compounds 3, 5, 9–11 and 13–17
The structures of compounds 3 (Fig. 1), 5 (Fig. 2), 9–11 (Fig. 3–
5) and 13–17 in the solid state were established by X-ray
crystallography. Crystallographic data are presented in Tables 1
and 2 while bond distances and angles are shown in Tables 3–
7. Compounds 3, 9 and 10 crystallize with two independent
molecules in the asymmetric unit but all corresponding bond
distances and angles are quite similar between the members
of each pair so only one molecule in each case is considered
for discussion. Compounds 3, 9 and 10 are examples of sym-
metrically and unsymmetrically substituted cyclodiphosphazanes
which show considerable differences in their bond parameters.
Symmetrically substituted cyclodiphosphazanes exhibit almost
identical endocyclic P–N bond distances and P–N–P angles,
whereas the unsymmetrically substituted derivatives show unequal
endocyclic P–N bond distances. Normally longer P–N bonds are
associated with the phosphorus atom having an exocyclic nitrogen
substituent and the shorter P–N bonds with those bearing oxo-,
alkoxy, aryloxy, or halo substituents. This difference is modest in
Scheme 4
The 31P NMR spectrum of 14b consists of four sets of
resonances: a doublet and a doublet of doublets, respectively at
2
2
9.8 and 126.2 ppm with JPPdP and JPNP couplings of 13.4 and
50.2 Hz, are assigned to PPh2 and ring phosphorus of the chelate
ring. The chemical shift values and coupling constants are almost
identical to those in 14a which clearly indicates that the initially
formed chelate ring remains almost intact during the course of
the reaction/crystallization. A doublet of doublets at 143.4 is due
to the ring phosphorus atom which forms a Pd–P s-bond after
P–O bond cleavage, whereas the PPh2 of the metallacycle shows
˚
cyclodiphosph(III)azans (ca. 0.04 A) but can be more significant
in chalcogen or imine derivatives of cyclodiphosph(V)azans. The
exocyclic P–N distances are always shorter and are comparable
with typical P–N distances observed in aminophosphines with
ample multiple bond character. The average P–N bond distance
a doublet (2JPPdP = 79.2 Hz) at 5.7 ppm. The JPPdP and JPNP
couplings are 79.2 and 50.2 Hz, respectively. The structure was
2
2
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the endocyclic P–N distances; the aryloxy associated P–N bonds
˚
(av. 1.662(2) A) being relatively shorter compared to the amide
˚
associated P–N bonds (av. 1.705(2) A). Interestingly there are no
significant differences in the P–N–P bond angles which are similar
˚
to those in 3 or 5. The exocyclic P3 S3 (1.9585(5) A) and P3 Se3
˚
(2.108(9) A) distances are slightly shorter than those of endocyclic
˚
˚
(av. P S, 1.9235(6) A; av. P Se, 2.080(1) A) P E bonds. In both
compounds, the folding of the P2N2 rings spans the range 8.0–9.2◦
while a slipped p-stacking interaction occurs between the phenyl
˚
ring C49–C54 and its counterpart at 2 - x, -y, 1 - z in 9 (3.39 A)
and the ring C25–C30 and its counterpart at 1 - x, -y, 2 - z in
˚
10 (3.35 A). Other significant intermolecular contacts in 9 are a
C–H ◊ ◊ ◊ p interaction (C53–H5◦3 ◊ ◊ ◊ centroid of the C55–C60 ring
˚
at 2 - x, -y, 1 - z; 2.72 A, 158 ) and a weak C–H ◊ ◊ ◊ S hydrogen
◦
˚
bond (C58–H58 ◊ ◊ ◊ S4 (at x, -1 + y, z); 2.91 A, 156 ). Similarly, 10
shows a C–H ◊ ◊ ◊ p interaction (C27–H27 ◊ ◊ ◊ centroid of the C19–
◦
˚
C24 ring at 1 - x, -y, 2 - z; 2.82 A, 160 ) and two weak C–H ◊ ◊ ◊ S◦e
Fig. 1 Molecular structure of (3). Thermal ellipsoids are drawn at the
50% probability level. Hydrogen atoms have been omitted for clarity.
˚
hydrogen bonds (C22–H22 ◊ ◊ ◊ Se2 (at x, -1 + y, z); 2.99◦A, 149
˚
and C11–H11a ◊ ◊ ◊ Se5 (at 1 - x, 1 - y, 1 - z); 2.93 A, 159 ).
The structure of rhodium complex 11 consists of two chelating
rings with two {RhCl(CO)} moieties each sharing an exocyclic and
an endocyclic phosphorus atom as shown in Fig. 5. The rhodium
centers are in slightly distorted square planar environments with
the CO ligand and the ring-P in a mutually cis orientation clearly
indicating the better p-acceptor ability of the ring phosphorus as
compared with the exocyclic phosphine moiety. This can be clearly
˚
in 3 is 1.708(3) A, whereas the average P–N–P bond angle is
98.01(15)◦. The endocyclic P1–N2 and P1–N3 distances in 5 are
˚
1.730(1) and 1.732(1) A, respectively, while the corresponding P2–
N2 (1.683(1) A) and P2–N3 (1.690(1) A) distances are slightly
shorter but are still long compared to the exocyclic P1–N1 distance
˚
˚
˚
of 1.656(1) A. The P2N2 rings in 3 are folded along the N ◊ ◊ ◊ N
axis by an average of 14.7◦ while in 5 the angle is only 5.4◦.
˚
visualized in their bond distances with Rh1–P2 (2.1653(8) A) and
˚
˚
Rh2–P3 (2.1665(8) A) being shorter compared to those associated
The average P–O bond distance (1.668(3) A) in 3 is slightly
shorter than the P2–O1 distance of 1.688(1) A in 5. The P–O
bond is significantly shorter in chalcogen derivatives 9 and 10
(av. 1.618(2) A). The exocyclic P–N bond distances in 9 and
˚
with exocyclic phosphine moiety (Rh1–P1, 2.3209(81); Rh2–P4,
˚
2.3275(8) A). The P1–Rh1–P2 and P3–Rh3–P4 bond angles are
92.05(3) and 91.05(3)◦, whereas the corresponding Cl–Rh–C bond
angles are 89.57(9) and 88.35(11)◦, respectively. The six-membered
˚
˚
10 show further shrinking (av. 1.622(2) A) compared to both
Fig. 2 Molecular structure of (5). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
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Fig. 3 Molecular structure of (9). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
Fig. 4 Molecular structure of (10). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
chelate rings are puckered and are orthogonal to the P2N2 ring
while the latter is folded along the N ◊ ◊ ◊ N axis by 11.2◦. There are
no significant differences in other bond distances between the two
sides of the complex and no notable intermolecular contacts.
The molecular structure of the diplatinum complex 13 (Fig. 6) is
very similar to that of the rhodium complex 11 with the platinum
centers in a typical square planar environment and the two six-
membered chelate rings orthogonal to the P2N2 ring while the
latter is folded along the N ◊ ◊ ◊ N axis by 10.9◦. The molecule
has crystallographically-imposed mirror symmetry with the mirror
plane perpendicular to the P ◊ ◊ ◊ P axis of the P2N2 ring and passing
through the nitrogen atoms. The P2–Pt1–P1 bond angle 93.01(4)◦,
whereas the corresponding Cl1–Pt1–Cl2 bond angle is 88.82(5)◦.
There are no significant differences in the P–N bond distances and
P–N–P bond angles and no significant intermolecular contacts.
The structure of dipalladium complex 14b is the first example
of a cyclodiphosphazane forming a six-membered chelate ring
on one arm and forming a Pd–P s-bond on the other through
a P–OPh bond cleavage followed by the oxidation of P(III) to
P(V); the broken fragment Ph2PC6H4O- coils around the same
palladium to form a five-membered palladacycle. The structure
3
indicates the presence of one molecule of coocrystallized [PdCl(h -
C3H5)]2 which is shared by four molecules of complex 14b. The
palladium atoms in 14b are in slightly distorted square planar
environments and are bridged by a P2N2 ring and a chloride ion
as shown in Fig. 7. The P2N2 ring has a fold angle of 16.0◦ while
the mean coordination planes of the two metals are inclined at
an angle of 20.7◦. The P1–Pd1–P2 and Cl1–Pd1–Cl2 bond angles
are 92.65(5)◦ and 87.79(11)◦, respectively. The corresponding P3–
Pd2–P3 and P3–Pd2–O2 bond angles are 94.51(5)◦ and 85.08(10)◦,
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Fig. 5 Molecular structure of (11). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
Table 1 Crystallographic information for 3, 5, 9, 10, 11 and 13
3
5
9
10
11
13
Formula
Fw
Crystal system
C44H46N2O2P4
758.71
Monoclinic
P21
9.0077(8)
29.659(3)
15.362(1)
90
104.984(1)
90
3964.6(6)
4
1.271
0.230
1600
100(2)
1.4–27.8
1.01
0.0566
0.1203
C30H42N3OP3
553.58
C30H42N3OP3S3
649.79
C30H42N3OP3Se3
790.46
C47H48Cl4N2O4P4Rh2
1176.37
Monoclinic
P21/c
10.3543(8)
28.627(2)
17.0271(13)
90
100.523(1)
90
4962.2(6)
4
1.575
1.054
2376
100(2)
2.1–27.6
1.04
0.0379
C44.5H47Cl5N2O2P4Pt2
1333.15
Monoclinic
P21/m
10.109(2)
25.000(5)
10.463(2)
90.000
108.739(2)
90.000
2504.1(9)
2
1.768
5.958
1269
220(2)
2.0–28.4
1.07
0.0380
Triclinic
Triclinic
Triclinic
¯
¯
¯
Space group
P1
P1
P1
˚
a/A
9.0386(4)
11.3565(4)
16.038(6)
74.097(1)
87.839(1)
85.701(1)
1578.54(11)
2
14.0885(9)
14.8388(10)
16.1937(11)
90.134(1)
97.004(1)
90.529(1)
3360.0(4)
4
14.091(1)
15.017(1)
16.446(1)
88.670(1)
81.503(1)
89.306(1)
3440.8(4)
4
˚
b/A
˚
c/A
a/◦
b/◦
g /◦
3
˚
V/A
Z
rc/g cm-3
m(MoKa)/mm-1
F(000)
1.165
0.214
592
200(2)
2.3–28
1.04
0.0392
0.1093
1.285
0.391
1376
100(2)
1.3–27.5
1.04
0.0356
1.526
3.374
1592
100(2)
2.0–28.4
0.99
0.0417
0.0981
T/K
q range/◦
GOF (F2)
R1
wR2
0.0940
0.0751
0.1004
whereas the Pd1–Cl2–Pd2 bond angle is 126.18(5)◦. In complex
The analogous dipalladium complex 15 containing the triphos
ligand 5 has slightly different structural features although obtained
in a similar reaction involving ligand 5 and [PdCl(h -C3H5)]2. The
molecular structure of 15 (Fig. 8) consists of a six-membered
chelate ring involving a PPh2 moiety and adjoining ring phospho-
rus atom with palladium in a typical square planar environment.
The chelate ring shows an upward puckering perpendicular to
the P2N2 ring and the Pd1–P1 and Pd1–P2 bond distances
˚
14b, the Pd–P s–bond distance (2.237(1) A) is slightly longer
3
compared to the Pd–P coordinate bond distances (av. Pd–P =
˚
˚
2.219(1) A). The terminal Pd1–Cl1 bond distance is 2.346(1) A,
whereas the two bridging Pd1–Cl2 and Pd2–Cl2 bond distances are
˚
˚
2.407(1) A and 2.399(1) A, respectively. The P2N2 ring shows two
˚
distinct P–N bond distances with P2–N1(1–652(5) A) and P2–N2
˚
(1.657(5) A) being considerably shorter compared to the P3–N1
˚
˚
˚
(1.734(5) A) and P3–N2 (1.740(5) A) bond distances associated
with the oxidized phosphorus atom but are comparable with
typical P(V)–N bond distances reported in the literature.1 Weak
intermolecular interactions include C17–H17 ◊ ◊ ◊ O2 (at 1 + x, y,
are 2.2306(8) and 2.2293(8) A, respectively. The amide bound
3
phosphorus atom is coordinated to a PdCl(h -C3H5) moiety
with Pd2–P3 and Pd2–Cl3 bond distances of 2.3541(8) A and
2.3873(9) A, respectively. The average P3–C(allyl) bond distance
is 1.816(1) A. The structures of gold complexes 16 and 17 (Fig. 9
˚
˚
◦
◦
˚
˚
˚
z; 2.63 A, 154 ), C10–H10 ◊ ◊ ◊ Cl2 (at 1 + x, y, z; 2.74 A, 151 ) and
C26–H26 ◊ ◊ ◊ O3 (at -1 + x, y, z; 2.39 A, 158 ).
◦
˚
and 10) reveal that all the phosphorus atoms are coordinated to
11154 | Dalton Trans., 2010, 39, 11149–11162
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Table 2 Crystallographic information for 14b–17
14b
15
16
17
Formula
Fw
C91H97Cl5N4O6P8Pd5
2299.74
C33H47Cl3N3OP3Pd2
913.84
C45H48Au4Cl6N2O2P4
1773.35
C30H42Au3Cl3N3OP3
1375.61
Crystal system
Triclinic
P1
Monoclinic
P21/n
Triclinic
P1
Triclinic
P1
¯
¯
¯
Space group
˚
a/A
10.9307(6)
14.9928(8)
16.6719(8)
115.282(1)
92.342(1)
99.743(1)
2415.2(2)
1
1.581
1.236
1154
100(2)
10.3506(13)
14.9616(18)
24.149(3)
90
91.218(2)
90
3738.9(8)
4
1.623
1.336
1848
100(2)
2.1–28.3
1.07
9.0756(11)
18.009(2)
19.531(3)
114.773(2)
96.465(2)
101.395(2)
2772.0(6)
2
2.125
10.894
1610
220(2)
11.2971(7)
12.8937(8)
16.465(1)
71.592(1)
71.147(1)
66.109(1)
2027.2(2)
2
2.049
11.171
1168
100(2)
˚
b/A
˚
c/A
a/◦
b/◦
g /◦
3
˚
V/A
Z
rc/g cm-3
m(MoKa)/mm-1
F(000)
T/K
q range/◦
GOF (F2)
R1
2.2–27.7
1.05
0.0488
2.1–28.0
1.04
0.0268
2.0–28.3
1.07
0.0415
0.0373
0.1006
wR2
0.1483
0.0620
0.1231
◦
˚
Table 3 Selected bond distances (A) and bond angles ( ) for compounds 3 and 5
3
5
P1–C13
P2–O2
P2–N1
P2–N2
P3–O1
P3–N1
P3–N2
P4–C32
N1–C19
N2–C23
P5–C57
P6–N3
P6–N4
P6–O3
P7–O4
P7–N4
P7–N3
P8–C76
N3–C63
N4–C67
1.850(4)
1.665(3)
1.711(3)
1.697(3)
1.670(3)
1.708(3)
1.717(3)
1.837(3)
1.483(5)
1.493(5)
1.841(4)
1.705(3)
1.694(3)
1.672(3)
1.667(3)
1.729(3)
1.707(3)
1.843(3)
1.487(5)
1.491(5)
N1–P2–N2
N1–P3–N2
N1–P2–O2
N1–P3–O1
P3–O1–C27
P2–O2–C18
P2–N1–P3
P2–N1–C19
P3–N1–C19
P2–N2–P3
P2–N2–C23
P3–N2–C23
N3–P6–N4
N3–P7–N4
P6–N3–P7
P6–N4–P7
P6–O3–C62
P7–O4–C71
N4–P6–O3
N4–P7–O4
81.18(14)
80.69(14)
105.15(14)
106.14(13)
127.8(2)
123.1(2)
97.90(15)
128.4(2)
P1–N1
P1–N2
P1–N3
P2–N2
P2–O1
P2–N3
O1–C13
P3–C18
P3–C25
P3–C19
N1–C1
N1–C5
N3–C9
1.6559(16)
1.7300(13)
1.7324(13)
1.6827(13)
1.6881(11)
1.6901(13)
1.3763(18)
1.8333(15)
1.8324(16)
1.8372(7)
1.473(2)
N1–P1–N2
N1–P1–N3
N2–P1–N3
N2–P2–N3
O1–P2–N2
O1–P2–N3
C18–P3–C19
C18–P3–C25
C19–P3–C25
P1–N2–P2
P1–N2–C5
P2–N2–C5
P1–N3–P2
P1–N3–C9
P2–N3–C9
P1–N1–C1
106.41(8)
103.99(7)
79.74(6)
82.30(6)
100.81(6)
101.80(6)
101.94(7)
101.09(7)
102.50(8)
99.02(6)
131.90(11)
129.07(11)
98.64(6)
129.8(2)
98.10(15)
128.5(2)
129.2(2)
1.473(2)
1.474(2)
81.37(14)
80.29(14)
98.25(15)
97.82(15)
123.1(2)
127.8(2)
101.82(14)
109.08(13)
127.70(11)
125.74(10)
129.77(14)
15–17, the fold angles of the P2N2 moieties are, respectively,
5.6◦, 2.3◦ and 3.0◦ and there are no notable intermolecular
interactions.
{AuCl} units to form tri- and tetranuclear complexes, respectively.
The Au–P bond distances are quite similar in the two complexes
˚
with the average to the terminal PPh2 ligand being 2.232(2) A
˚
while those to the ring phosphorus atoms average 2.202(2) A.
In complex 16, the Cl3–Au3–P3 (177.74(4)◦) and Cl4–Au4–P4
(178.19(5)◦) bond angles are almost linear and comparable to the
same in analogous complexes. Interestingly, the other two bond
angles, Cl2–Au2–P2 (166.79(5)◦ and Cl1–Au1–P1 (170.48(4)◦) are
bent remarkably towards each other owing to the intramolecular
aurophilic interaction which is clearly echoed in the Au1 ◊ ◊ ◊ Au2
Conclusions
The reactions of cis-[tBuNPCl]2 and cis[tBuNH(tBuN)2PCl]
with 2-diphenylphosphinophenol afford the first examples of
bis(phosphine) and mixed phosphine-amide derivatives in quanti-
tative yields. Previously we have demonstrated the versatile coor-
dination behavior of cyclodiphosphazanes with N, S or O-donor
functionalities which resulted in interesting metal complexes
with interesting structural features. Cyclodiphosphazanes with
bis(phosphine) functionalities offer an opportunity to make either
bischelated complexes containing the same metal or two different
metals. On the other hand, the cyclodiphosphazane containing
both phosphine and amide functionalities can conveniently form
˚
distance of 3.2699(6) A. The other two gold atoms do not show
any such interaction, which is evident from the Au3–Au4 distance
˚
of 4.836 A. In complex 17, all Cl–Au–P bond angles [Cl1–Au1–P1,
174.84(10)◦; Cl2–Au2–P2, 177.36(8)◦; Cl3–Au3–P3, 172.37(2)◦]
are distinctly different and there is no inter- or intramolecular
aurophilic interaction. The P–N and P–O bond distances 16 and
17 are comparable to those in rest of the complexes. In complexes
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◦
˚
Table 4 Selected bond distances (A) and bond angles ( ) for 9 and 10
Compound 9
Compound 10
P1–N1
P1–N2
P1–N3
P1–S1
P2–N1
P2–O1
P2–N3
P2–S2
P3–C25
P3–C19
P3–C18
P3–S3
P4–N4
P4–N5
P4–N6
P4–S4
P5–N6
P5–N4
P5–O2
P5–S5
1.7054(14)
1.6248(14)
1.7024(14)
1.9268(6)
1.6552(14)
1.6172(12)
1.6659(14)
1.9203(6)
1.8252(16)
1.8098(16)
1.8207(15)
1.9585(5)
1.7043(13)
1.6240(14)
1.7039(14)
1.9303(6)
1.6657(13)
1.6546(14)
1.6175(11)
1.9242(6)
N1–P1–N2
N1–P1–N3
N1–P2–N3
N2–P1–N3
O1–P2–S2
O1–P2–N3
P1–N1–P2
P1–N1–C1
P2–N1–C1
P1–N3–P2
P1–N3–C9
P2–N3–C9
P4–N4–P5
P4–N4–C31
P5–N4–C31
P4–N6–P5
P4–N6–C39
P5–N6–C39
O1–P2–S2
O2–P5–S5
108.98(7)
82.81(7)
85.48(7)
108.62(7)
114.68(5)
108.98(6)
95.64(7)
130.57(11)
130.00(11)
95.36(7)
131.19(11)
129.68(11)
95.96(7)
131.28(11)
129.35(11)
94.56(7)
131.56(11)
130.15(11)
114.68(5)
114.55(5)
P1–N1
P1–N2
P1–O1
P1–Se1
P2–N1
P2–N2
P2–N3
P2–Se2
P3–C18
P3–C19
P3–C25
P3–Se3
P4–N4
P4–N5
P4–O2
P4–Se4
P5–N4
P5–N5
P5–N6
P5–Se5
1.662(3)
1.666(3)
1.618(2)
2.0788(9)
1.706(3)
1.705(3)
1.621(3)
2.0828(8)
1.811(3)
1.833(3)
1.808(3)
2.108(9)
1.657(3)
1.659(3)
1.619(2)
2.0735(9)
1.703(3)
1.707(3)
1.622(3)
2.0791(9)
N1–P1–N2
N1–P2–N2
N1–P2–N3
N2–P2–N3
Se1–P1–O1
P1–N1–P2
P1–N1–C1
P2–N1–C1
P2–N2–C5
P1–N2–C5
P2–N3–C9
P4–N4–P5
P4–N4–C31
P5–N4–C31
P4–N5–P5
P4–N5–C35
P5–N5–C35
85.07(12)
82.56(12)
110.40(13)
108.16(13)
115.43(9)
95.92(13)
129.7(2)
131.7(2)
131.7(2)
129.7(2)
134.3(2)
95.84(13)
131.1(2)
129.8(2)
95.60(13)
130.1(2)
131.0(2)
◦
˚
Table 5 Selected bond distances (A) and bond angles ( ) for 11 and 13
Compound 11
Compound 13
Rh1–P1
Rh1–P2
Rh1–Cl1
Rh1–C19
C19–O3
Rh2–P3
Rh2–P4
Rh2–Cl2
Rh2–C46
C46–O4
P2–N1
P2–N2
P3–N1
P3–N2
P2–O1
P3–O2
N1–C20
N2–C24
2.3210(9)
2.1653(8)
2.3851(8)
1.905(3)
1.126(4)
2.1664(9)
2.3274(8)
2.3647(9)
1.890(4)
1.119(5)
1.694(2)
1.699(3)
1.690(2)
1.686(3)
1.638(2)
1.653(2)
1.488(4)
1.495(4)
P1–Rh1–P2
P1–Rh1–Cl1
Cl1–Rh1–C19
P2–Rh1–C19
P3–Rh2–P4
P3–Rh2–C46
Cl2–Rh2–C46
P4–Rh2–Cl2
N1–P2–N2
N1–P3–N2
P2–N1–P3
P2–N1–C20
P3–N1–C20
P2–N2–P3
P2–N2–C24
P3–N2–C24
92.05(3)
88.01(3)
89.56(10)
91.24(10)
91.05(3)
92.71(11)
88.35(11)
87.85(3)
82.76(12)
83.27(12)
96.42(13)
130.84(19)
131.6(2)
96.32(13)
130.6(2)
131.9(2)
Pt1–Cl1
Pt1–Cl2
Pt1–P1
Pt1–P2
P1–N1
P1–N2
P1–O1
2.3213(15)
2.3254(13)
2.1869(13)
2.2447(13)
1.677(4)
1.690(4)
1.626(3)
Cl1–Pt1–Cl2
Cl1–Pt1–P1
Cl1–Pt1–P2
P1–Pt1–P2
Cl2–Pt1–P1
Cl2–Pt1–P2
Cl3–Pt2–P3
P1–N1–P1a
P1–N1–C23
P1–N2–P1a
P1–N2–C19
N1–P1–N2
88.82(5)
90.97(5)
174.13(6)
93.01(4)
169.68(5)
88.03(4)
91.34(7)
95.7(3)
132.11(14)
94.8(2)
132.60(14)
84.1(2)
N1–C23
N2–C19
1.474(9)
1.494(8)
◦
˚
Table 6 Selected bond distances (A) and bond angles ( ) for 14b and 15
Compound 14b
Compound 15
Pd1–Cl1
Pd1–Cl2
Pd1–P1
Pd1–P2
Pd2–Cl2
Pd2–P3
Pd2–P4
Pd2–O2
P2–N1
P2–N2
P2–O1
P3–O3
P3–N1
2.3462(12)
2.4071(12)
2.2251(13)
2.2121(13)
2.3986(13)
2.2370(13)
2.2199(13)
2.087(3)
1.652(5)
1.657(5)
1.609(4)
1.477(3)
1.734(5)
1.740(5)
1.479(8)
1.484(8)
2.393(4)
2.286(12)
Cl1–Pd1–Cl2
Cl1–Pd1–P1
Cl1–Pd1–P2
P1–Pd1–P2
Cl2–Pd1–P2
Cl2–Pd2–P3
Cl2–Pd2–P4
Cl2–Pd2–O2
P4–Pd2–O2
P3–Pd2–P4
P2–N1–P3
P2–N1–C19
P3–N1–C19
P2–N2–P3
P2–N2–C41
P3–N2–C41
N1–P2–N2
N1–P3–N2
87.79(4)
90.37(4)
176.16(5)
92.65(5)
89.06(4)
93.65(4)
171.79(4)
86.80(9)
85.08(10)
94.51(5)
95.5(3)
132.7(4)
131.6(4)
95.0(3)
130.3(4)
131.4(4)
86.0(2)
Pd1–Cl1
Pd1–Cl2
Pd1–P1
Pd1–P2
Pd2–Cl3
Pd2–P3
P1–C1
2.3351(8)
2.352915)
2.2307(8)
2.2292(8)
2.3873(9)
2.3541(8)
1.813(3)
1.808(3)
1.802(3)
1.633(2)
1.656(3)
1.669(3)
1.631(2)
1.734(3)
1.730(3)
1.631(2)
Cl1–Pd1–Cl2
Cl1–Pd1–P1
Cl1–Pd1–P2
P1–Pd1–P2
Cl2–Pd1–P2
Cl2–Pd1–P1
Cl3–Pd2–P3
Cl3–Pd2–C31
Cl3–Pd2–C32
Cl3–Pd2–C33
N1–P2–N2
N1–P3–P2
91.20(4)
89.73(3)
170.43(4)
92.68(3)
89.15(4)
163.35(5)
96.00(3)
157.20(11)
124.82(12)
90.97(9)
84.98(13)
80.85(13)
97.09(14)
131.1(3)
131.8(3)
96.78(15)
130.1(2)
131.0(2)
P1–C13
P1–C7
P2–O1
P2–N1
P2–N2
P3–N3
P3–N1
P3–N2
P3–N3
P2–N1–P3
P3–N2
P2–N1–C27
P3–N1–C27
P2–N2–P3
P2–N2–C23
P3–N2–C23
N1–C19
N2–C41
Pd3–Cl3
Pd3–C45
81.1(2)
11156 | Dalton Trans., 2010, 39, 11149–11162
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◦
˚
Table 7 Selected bond distances (A) and bond angles ( ) for 16 and 17
Compound 16
Compound 17
Au1–Cl1
Au1–P1
Au2–Cl2
Au2–P2
Au3–P3
Au3–Cl3
Au4–P4
Au4–Cl4
P2–N1
P2–N2
P2–O1
P3–N1
P3–N2
2.2974(14)
2.2285(13)
2.277(2)
2.1983(14)
2.2072(11)
2.2700(10)
2.2340(11)
2.2757(15)
1.712(3)
1.683(4)
1.630(3)
1.693(3)
1.672(3)
Cl1–Au1–P1
Cl2–Au2–P2
Cl3–Au4–P3
C14–Au4–P4
P2–N1–P3
P2–N1–C1
P3–N1–C1
P2–N2–P3
P2–N2–C5
P3–N2–C5
N1–P2–N2
N1–P3–N2
170.48(5)
166.79(5)
177.74(4)
178.19(6)
94.65(16)
129.4(3)
124.1(3)
96.53(17)
134.0(3)
129.3(3)
83.89(17)
84.81(17)
Au1–Cl1
Au1–P1
Au2–Cl2
Au2–P2
Au3–P3
Au3–Cl3
P1–O
P1–N1
P1–N2
P2–N1
P2–N2
2.271(3)
2.199(2)
2.277(3)
2.212(2)
2.234(2)
2.285(2)
1.627(7)
1.646(7)
1.683(8)
1.709(7)
1.699(7)
1.620(7)
1.815(9)
1.819(9)
1.813(8)
Cl1–Au1–P1
Cl2–Au2–P2
Cl3–Au4–P3
C14–Au4–P4
N1–P1–N2
N1–P2–N2
P1–N1–P2
P1–N1–C1
P2–N1–C1
P1–N2–P2
P1–N2–C5
P2–N2–C5
P2–N3–C9
174.84(10)
177.36(8)
172.37(8)
177.2(3)
84.7(4)
82.3(3)
97.0(3)
132.3(6)
130.6(6)
96.0(3)
128.4(6)
129.2(6)
132.8(6)
P2–N3
P3–C18
P3–C19
P3–C25
P3–O2
N1–C1
1.592(3)
1.526(5)
N2–C23
Au1 ◊ ◊ ◊ Au2
Au3 ◊ ◊ ◊ Au4
1.506(5)
3.2699(6)
4.836
Fig. 6 Molecular structure of (13). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
a chelate complex with platinum metals whereas the amide
functionality can perform as an anionic ligand towards high valent
Experimental
General procedures
early metals. This kind of complex with two disparate metals
in close proximity but without metal–metal bonding may find
interesting applications in catalysis as activation of molecules
would be lot easier due to the difference in the polarizing ability
of the metal centers. The amide bound metal can perform as an
electrophilic center whereas the chelated late metal or platinum
metal centers can facilitate nucleophilic reactions. Exploration
of these reactions with appropriate metals is currently ongoing.
Another important aspect concerned with the cyclodiphosphaz-
All manipulations were performed under rigorously anaerobic
conditions using Schlenk techniques. All the solvents were purified
by conventional procedures and distilled prior to use.16 The
compounds cis-{ BuNPCl}2 (1),17 cis-{ Bu(H)NP(m-tBuN)2PCll}
t
t
(2),18 Ph2PC6H4OH-o,12 Ph2PC2H4OH,13 [Rh(CO)2Cl]2,19 [Pd(h -
3
C3H5)Cl]2 and AuCl(SMe2)21 were prepared according to the
20
published procedures. Other chemicals were obtained from com-
mercial sources and purified prior to use.
2
ane derivatives is the JPNP couplings in their 31P NMR spectra.
Some cyclodiphosphazane derivatives and their metal complexes
show JPNP values and others do not and at present we do not
Instrumentation
2
1
1
The H and 31P{ H} NMR (d in ppm) spectra were recorded
using Varian VXR 300 or VXR 400 spectrometer operating
at the appropriate frequencies using TMS and 85% H3PO4 as
internal and external references, respectively. The microanaly-
ses were performed using Carlo Erba Model 1112 elemental
have clear explanation. It would be interesting to analyze the
spectra with the support of X-ray structures to correlate the extent
of ring puckering and its possible influence on the magnitude
of the PNP coupling. The work in this direction is also in
progress.
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Fig. 7 Molecular structure of (14b). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
Fig. 8 Molecular structure of (15). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
analyzer. Infrared spectra were recorded on a Nicolet Impact
400 FTIR instrument as a KBr disk. Q-Tof Micromass exper-
iments were carried out using Waters Q-Tof micro (YA-105).
The melting points were observed in capillary tubes and are
uncorrected.
added dropwise a solution of cis-(tBuNPCl)2 (3.21 g, 11.67 mmol)
◦
also in diethyl ether (20 mL) at -25 C. After the completion of
◦
the addition, the reaction mixture was warmed to 25 C stirring
was continued for a further period of 12 h at room temperature
and then filtered through Celite. All the solvents were removed
under vacuum leaving a white solid. Yield: 78% (6.91 g). Mp: 170–
172 ◦C. Anal. Calcd. for C44H46P4O2N2: C, 69.65; H, 6.11; N, 3.69.
Found: C, 69.62; H, 6.10; N, 3.62. 1H NMR (400 MHz, CDCl3):
t
Synthesis of cis-{ BuNPOC6H4PPh2-o}2 (3)
1
d 1.15 (s, tBu, 18H), 6.76–7.77 (m, Ph, 28H). 31P{ H} NMR (162
To a mixture of OHC6H4PPh2-o (6.493 g, 23.34 mmol) and
triethylamine (2.363 g, 23.34 mmol) in diethyl ether (150 mL), was
MHz, CDCl3): d 132.0 (d), -20.4 (d), 2JPP = 12.3 Hz.
11158 | Dalton Trans., 2010, 39, 11149–11162
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Fig. 9 Molecular structure of (16). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
Fig. 10 Molecular structure of (17). Thermal ellipsoids are drawn at the 50% probability level. Hydrogen atoms have been omitted for clarity.
t
t
Synthesis of cis-{ BuNPOCH2CH2PPh2}2 (4)
Synthesis of cis-{ Bu(H)NP(l-tBuN)2POC6H4PPh2-o} (5)
The procedure is similar to that of 3 using cis-(tBuNPCl)2
(2.263 g, 8.23 mmol), triethylamine (1.750 g, 17.28 mmol) and
HOC2H4PPh2 (3.977 g, 17.28 mmol). Yield: 89% (4.871 g). Anal.
Calcd. for C36H46P4O2N2: C, 65.25; H, 7.00; N, 4.23. Found: C,
A mixture of HOC6H4PPh2-o (1.440 g, 5.180 mmol) and triethy-
lamine (0.524 g, 5.180 mmol) in diethyl ether (20 mL) was added
t
dropwise into an ice cold solution of cis-{ BuHN(tBuNP)2Cl}
(1.616 g, 5.180 mmol) in diethyl ether (60 mL). The reaction
mixture was stirred for 12 h at room temperature and then filtered
through Celite. All the solvents were removed under vacuum to
give a white solid, which was crystallized from a 1 : 1 mixture
of dichloromethane and acetonitrile. Yield: 90% (2.588 g). Mp:
1
65.51; H, 6.76; N, 4.67. H NMR (400 MHz, CDCl3): d 1.19 (s,
tBu, 18H), 2.34 (m, CH2, 4H), 3.93 (m, OCH2, 4H), 7.45–7.16 (m,
1
Ph, 20H). 31P{ H} NMR (162 MHz, CDCl3): d 131.0 (s), -25.0
(s).
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156–158 ◦C. Anal. Calcd. for C30H42P3ON3: C, 65.09; H, 7.65;
N, 7.59. Found: C, 65.22; H, 7.67; N, 7.62. 1H NMR (400 MHz,
CDCl3): d 1.19 (s, tBu, 18H), 1.23 (s, tBu, 9H), 3.31 (d, NH, 1H,
18H), 1.55 (s, tBu, 9H), 5.23 (s, NH, 1H), 6.73–9.16 (m, Ph, 14H).
1
31P{ H} NMR (162 MHz, CDCl3): d 40.5 (d, 2JPP = 34.5 Hz), 38.5
(d, 2JPP = 34.5 Hz), 38.1 (s, PPh2).
1
2JPH = 8.4 Hz), 6.57–7.38 (m, Ph, 14H). 31P{ H} NMR (162 MHz,
CDCl3): d 144.5 (d, 2JPP = 13.4 Hz), 116.3 (d, 2JPP = 13.3 Hz), -16.5
(s, PPh2).
t
Synthesis of cis-{ BuNH(tBuNP(Se))2OC6H4P(Se)Ph2} (10)
The procedure is similar to that of 9 using 5 (0.050 g, 0.090 mmol)
and selenium (0.021 g, 0.270 mmol). Yield: 88% (0.063 g). Mp:
254–256 ◦C. Anal. Calcd. for C30H42P3N3OSe3: C, 45.58; H, 5.36;
N, 5.32. Found: C, 45.70; H, 5.32; N, 5.66. 1H NMR (400 MHz,
CDCl3): d 1.37 (s, tBu, 18H), 1.59 (s, tBu, 9H), 5.66 (d, NH, 1H,
t
Synthesis of cis-{ Bu(H)NP(l-tBuN)2POCH2CH2PPh2} (6)
A mixture of HOCH2CH2PPh2 (0.550 g, 2.400 mmol) and
triethylamine (0.242 g, 2.400 mmol) in diethyl ether (20 mL) was
t
added dropwise into an ice cold solution of cis-{ Bu(H)NP(m-
tBuN)2PCl} (0.678 g, 2.170 mmol) also in diethyl ether (50 mL).
The reaction mixture was stirred for 12 h at room temperature
and then filtered through Celite. All the solvents were removed
under vacuum to give analytically pure product of 6 as a colorless
viscous liquid. Yield: 83% (0.910 g). Anal. Calcd. for C26H42P3N3O:
C, 61.77; H, 8.37; N, 8.31. Found: C, 61.24; H, 8.73; N, 8.26. 1H
NMR (400 MHz, CDCl3): d 1.19 (s, tBu, 18H), 1.23 (s, tBu, 9H),
1.19 (s, tBu, 18H), 2.34 (m, CH2, 4H), 3.93 (m, OCH2, 4H), 7.45–
2JPH = 2.8 Hz), 6.72–9.57 (m, Ph, 14H). 31P{ H} NMR (162 MHz,
1
2
CDCl3): d 27.3 (s, PPh2, JSeP = 733 Hz), 25.0 (d, JPP = 16.7 Hz,
JSeP = 941 Hz), 24.4 (d, 2JPP = 16.7 Hz, JSeP = 887 Hz).
t
Synthesis of [Rh2Cl2(CO)2{ BuNPOC6H4PPh2}2] (11)
A solution of [Rh(CO)2Cl]2 (0.015 g, 0.040 mmol) in 10 mL
of dichloromethane was added dropwise to a well-stirred
dichloromethane (10 mL) solution of 3 (0.030 g, 0.040 mmol)
at room temperature. The reaction mixture was stirred for 4 h,
concentrated to 4 mL, layered with 5 mL of diethyl ether and
7.16 (m, Ph, 20H) 6.5–7.4 (m, Ph, 14H). 31P{ H} NMR (162 MHz,
1
CDCl3): d 112.3 (s), 92.9 (s), -25.1 (s).
t
Synthesis of cis-{ BuNP(S)OC6H4P(S)Ph2}2 (7)
◦
kept at -30 C for a day to get a pure yellow crystalline product
A solution of 3 (0.076 g, 0.100 mmol) and elemental sulfur (0.013 g,
0.400 mmol) in toluene (20 mL) was refluxed for 24 h. The
reaction mixture was cooled to room temperature, filtered through
Celite and all the solvents were removed under vacuum to get a
white solid. The solid residue was dissolved in a 1 : 1 mixture of
dichloromethane and acetonitrile and stored at 0 ◦C for 24 h to give
an analytically pure produc◦t of 7 as a white crystalline solid. Yield:
87% (0.077 g). Mp: >250 C. Anal. Calcd. for C44H46P4N2O2S4:
C, 59.58; H, 5.23; N, 3.16; S, 14.46. Found: C, 59.32; H, 5.41; N,
3.40; S, 14.48. 1H NMR (400 MHz, CDCl3): d 1.18 (s, tBu, 18H),
of 11. Yield: 84% (0.037 g). Mp: >260 ◦C. Anal. Calcd. for
C46H46P4N2O4Rh2Cl2: C, 50.62; H, 4.25; N, 2.57. Found: C, 50.49;
H, 4.18; N, 2.41. 1H NMR (400 MHz, CDCl3): d 1.21 (s, tBu, 18H),
1
6.69–7.56 (m, Ph, 28H). 31P{ H} NMR (162 MHz, CDCl3): d 136.8
2
1
(m, JRhP = 201 Hz), 9.9 (m, JPRhP = 49.5 Hz, JRhP = 124.8 Hz).
FT-IR (KBr disc: cm-1): 2051, 2033 [nCO]. MS (EI): m/z 1028.02
[M - Cl·CO]+.
t
Synthesis of cis,cis-[(PdCl2)2{ BuNPOC6H4PPh2-o}2] (12)
6.88–8.77 (m, Ph, 28H). 31P{ H} NMR (162 MHz, CDCl3): d 38.7
1
A
solution of [Pd(COD)Cl2] (0.045 g, 0.158 mmol) in
(s), 38.0 (s).
dichloromethane (5 mL) was added dropwise to a solution of
3 (0.060 g, 0.079 mmol) also in dichloromethane (5 mL). The
reaction mixture was left undisturbed for two days to give
analytically pure pale yellow crystals of 12. Yield: 92% (0.081 g).
Mp: >240 ◦C. Anal. Calcd. for C44H46P4N2O2Pd2Cl4: C, 47.46; H,
t
Synthesis of cis-{ BuNP(Se)OC6H4P(Se)Ph2}2 (8)
The procedure is similar to that of 7 using 3 (0.076 g, 0.100 mmol)
and selenium (0.032 g, 0.400 mmol). Yield: 93% (0.100 g). Mp:
>250 ◦C. Anal. Calcd. for C44H46P4N2O2Se4: C, 49.18; H, 4.31;
N, 2.61. Found: C, 49.09; H, 4.39; N, 2.75. 1H NMR (400 MHz,
1
4.16; N, 2.51. Found: C, 47.37; H, 4.19; N, 2.42. H NMR (400
t
MHz, DMSO-d6): d 1.22 (s, Bu, 18H), 6.55–7.76 (m, Ph, 28H).
t
1
1
CDCl3): d 1.21 (s, Bu, 18H), 6.82–8.62 (m, Ph, 28H). 31P{ H}
31P{ H} NMR (162 MHz, DMSO-d6): d 98.0 (d, ring Ps), 10.2 (d,
NMR (162 MHz, CDCl3): d 29.1 (s, JSeP = 747 Hz), 27.5 (s, JSeP
=
PPh2, 2JPP = 39 Hz).
996 Hz).
t
t
Synthesis of cis-{ BuNH(tBuNP(S))2OC6H4P(S)Ph2} (9)
Synthesis of cis,cis-[(PtCl2}2{ BuNPOC6H4PPh2-o}2] (13)
A solution of 5 (0.050 g, 0.090 mmol) and elemental sulfur (0.009 g,
0.270 mmol) in toluene (20 mL) was refluxed for 24 h. The
reaction mixture was cooled to room temperature, filtered through
Celite and all the solvents were removed under vacuum to give a
white solid. The solid residue was dissolved in a 1 : 1 mixture of
dichloromethane and acetonitrile and stored at 0 ◦C for 24 h to give
an analytically pure product of 9 as a white crystalline solid. Yield:
91% (0.053 g). Mp: 196–198 ◦C. Anal. Calcd. for C30H42P3N3OS3:
C, 55.45; H, 6.51; N, 6.47; S, 14.80. Found: C, 55.48; H, 6.59;
A solution of [Pt(COD)Cl2] (0.040 g, 0.105 mmol) in
dichloromethane (5 mL) was added dropwise to a solution of
3 (0.040 g, 0.053 mmol) in the same solvent (5 mL) and the
reaction mixture was left undisturbed for two days to give colorless
crystals of 13. Yield: 96% (0.066 g). Mp: >260 ◦C. Anal. Calcd. for
C44H46P4N2O2Pt2Cl4: C, 40.94; H, 3.59; N, 2.17. Found: C, 41.07;
H, 3.59; N, 2.22. 1H NMR (400 MHz, DMSO-d6): d 1.05 (s, tBu,
1
18H), 6.55–7.76 (m, Ph, 28H). 31P{ H} NMR (162 MHz, DMSO-
d6): d 90.0 (d, JPtP = 5522 Hz), -5.7 (d, PPh2, JPtP = 3151 Hz), 2JPP
=
1
t
N, 6.52; S, 14.71. H NMR (400 MHz, CDCl3): d 1.31 (s, Bu,
51.5 Hz.
11160 | Dalton Trans., 2010, 39, 11149–11162
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1
Synthesis of [Cl2Pd{l-(g2-PPh2C6H4OP(l-tBuN)2P(O)}(l-
Cl)Pd(g2-OC6H4Ph2P)] (14b)
3.36. Found: C, 28.86; H, 3.27; N, 3.40. H NMR (400 MHz,
t
t
CDCl3): d 1.44 (s, Bu, 18H), 1.68 (s, Bu, 9H), 4.72 (d, NH,
1H, JPH = 8.4 Hz), 6.84–8.72 (m, Ph, 14H). 31P{ H} NMR
2
1
3
A solution of [Pd(h -C3H5)Cl]2 (0.048 g, 0.132 mmol) in
2
(162 MHz, CDCl3): d 88.9 (d), 71.0 (d), JPP = 8.9 Hz, 19.1
dichloromethane (10 mL) was added dropwise to a solution of
3 (0.050 g, 0.066 mmol) also in dichloromethane (10 mL) at room
temperature. The reaction mixture was stirred for 4 h, concentrated
to 4 mL, then diluted with a few drops of diethyl ether and stored
at room temperature for 2 days to give pale yellow crystals of
14b. Yield: 68% (0.046 g). Mp: 190 ◦C (dec.). Anal. Calcd. for
C45.5H48.50Cl2.50N2O3P4Pd2.50: C, 47.52; H, 4.25; N, 2.43. Found: C,
(s, PPh2).
X-Ray crystallography†
A crystal of each of the compounds 3, 5, 9–11, and 13–17 suitable
for X-ray crystal analysis was mounted in a CryoloopTM with a
drop of paratone oil and placed in the cold nitrogen stream of the
KryoflexTM attachment of the Bruker APEX CCD diffractometer.
Full spheres of data were collected using 606 scans in w (0.3◦ per
scan) at f = 0, 120 and 240◦ (3, 9, 13 and 16) or a combination
of three sets of 400 scans in w (0.5◦ per scan) at j = 0, 90
and 180◦ plus two sets of 800 scans in j (0.45◦ per scan) at
w = -30 and 210◦ (5, 10, 11, 14b, 15 and 17), all under the
control of the SMART22 (3, 9, 10, 15, 17) or APEX223 (5, 11,
13, 14b, 16) software packages. For 11, inspection of reciprocal
lattice displays of selected reflections taken from the full data set
gave definite evidence for twinning. Processing of these reflections
with CELL_NOW24 showed that the crystal of 11 possessed a
primitive monoclinic cell twinned by a 180◦ rotation about a. The
raw data were reduced to F2 values using the SAINT software25
and global refinements of unit cell parameters using 3871–9981
reflections chosen from the full data sets were performed. Multiple
measurements of equivalent reflections provided the basis for
empirical absorption corrections as well as corrections for any
crystal deterioration during the data collection (SADABS26 for all
but 11 where TWINABS27 was used. Additionally, an analytical
absorption correction was used for 16). All the structures were
solved by direct methods, except for 11, 16 and 17 where Patterson
methods were employed, and refined by full-matrix least-squares
procedures using the SHELXTL program package.28 Hydrogen
atoms attached to carbon were placed in calculated positions while
those attached to nitrogen were placed in locations derived from
a difference map. All were included as riding contributions with
isotropic displacement parameters tied to those of the attached
non-hydrogen atoms.
In the refinement of 3 it soon became evident from the inter-
mediate value of the Flack parameter29 (0.31(7)) that the crystal
was a racemic twin (hence the presence of non-crystallographic
inversion symmetry) and the refinement was completed by treating
it as such. In the final refinement of 11, a comparison was made of
the model obtained using the single-component reflection data
extracted from the full twinned data set by TWINABS with
that obtained using the two-component reflection data leading
to the conclusion that the former provided a superior result.
In the cases of 13, 16 and 17, residual density peaks remained
in the difference maps calculated at the end of the refinement
of the main molecule(s). As these were well-separated from the
molecule of interest, they were judged to be lattice solvent but were
sufficiently diffuse that attempts at modeling them as reasonable
solvent molecules, even with moderate disorder, proved unsuc-
cessful. Consequently, they were removed with the SQUEEZE
option in PLATON.30 This necessarily leads to the presence
of void space in the model reported. Pertinent crystallographic
data and other experimental details are summarized in Tables 1
and 2.
1
47.65; H, 4.22; N, 2.33. H NMR (400 MHz, CDCl3): d 1.04
t
(s, Bu, 18H), 2.91–5.80 (allyl, 10H), 6.69–7.88 (m, Ph, 28H).
1
2
31P{ H} NMR (162 MHz, CDCl3): d 143.4 (dd, JPP = 50.2 Hz,
2JPP = 79.2 Hz, P(O)–Pd, s-bonded), 126.2 (dd, JPP = 50.2 Hz,
2
4JPP = 13.4 Hz; P of cyclodiphosphazane in chelate ring), 9.8 (d,
2JPPdP = 13.4 Hz; chelated PPh2), 5.7 (d, JPP = 79.2 Hz; PPh2 of
2
palladacyle).
t
Synthesis of [Pd2Cl3(g3-C3H5)tBuNH{ BuNP}2OC6H4PPh2] (15)
3
A solution of [Pd(h -C3H5)Cl]2 (0.025 g, 0.069 mmol) in
dichloromethane (5 mL) was added dropwise to a solution of
5 (0.025 g, 0.046 mmol) in the same solvent (10 mL) at room
temperature. The reaction mixture was stirred for 4 h, concentrated
to 3 mL, diluted with 3 mL of diethyl ether and stored at -30 ◦C
for 24 h to give an analytically pure ◦yellow crystalline product
of 15. Yield: 76% (0.032 g). Mp: 160 C (dec.). Anal. Calcd. for
C33H47P3N3OPd2Cl3: C, 43.37; H, 5.18; N, 4.60. Found: C, 43.44;
1
t
H, 5.32; N, 4.92. H NMR (400 MHz, CDCl3): d 1.44 (s, Bu,
18H), 1.57 (s, tBu, 9H), 3.49 (d, NH, 1H, 2JPH = 8.4 Hz), 6.67–7.69
1
(m, Ph, 14H). 31P{ H} NMR (162 MHz, CDCl3): d 99.6 (d, 2JPP
42.3), 90.9 (dd, 2JPP = 42.3; 2JPP = 11.2 Hz), -9.5 (d, PPh2, 2JPP
11.2 Hz). MS (EI): m/z 877.93 [M - Cl]+.
=
=
Synthesis of [Au4Cl4{(tBuNP)OC6H4PPh2}2] (16)
A dichloromethane (10 mL) solution of [AuCl(SMe2)] (0.062 g,
0.211 mmol) was added dropwise to a well-stirred solution (5 mL)
of 3 (0.040 g, 0.053 mmol) at room temperature. The reaction
mixture was stirred further for 4 h. The solution was concentrated,
diluted with a few drops of diethyl ether and stored at room
temperature for 24 h to give colorless needle like crystals of
9. Yield: 90% (0.081 g). Mp: 224 ◦C (dec.). Anal. Calcd. for
C44H46P4N2O2Pt4Cl4: C, 31.30; H, 2.75; N, 1.66. Found: C, 31.30;
1
t
H, 2.75; N, 1.66. H NMR (400 MHz, CDCl3): d 1.27 (s, Bu,
1
18H), 6.70–7.81 (m, Ph, 28H). 31P{ H} NMR (162 MHz, CDCl3):
d 101.4 (s), 21.9 (s).
t
Synthesis of [tBuNH{ BuNP(AuCl)}2OC6H4PPh2(AuCl)] (17)
A dichloromethane (7 mL) solution of [AuCl(SMe2)] (0.055 g,
0.187 mmol) was added dropwise to a well-stirred solution (10 mL)
of 5 (0.035 g, 0.062 mmol) at room temperature. The reaction
mixture was stirred further for 4 h, then concentrated to 4 mL
and stored at room temperature for 24 h to give analytically
pure colorless crystals of 17. Yield: 82% (0.064 g). Mp: 230 ◦C
(dec.). Anal. Calcd. for C30H42P3N3OAu3Cl3: C, 28.81; H, 3.38; N,
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Acknowledgements
We are grateful to the Department of Science and Technology
(DST), New Delhi, for financial support of this work through grant
SR/S1/IC-02/007. We also thank the Department of Chemistry
Instrumentation Facilities, Bombay, for spectral and analytical
data and J. T. M thanks the Louisiana Board of Regents for pur-
chase of the CCD diffractometer and the Chemistry Department
of Tulane University for support of the X-ray laboratory.
11 D. Suresh, M. S. Balakrishna and J. T. Mague, Dalton Trans., 2008,
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