New 10-membered inorganic heterocyclic diphosphanes, PhN(PX)2{(-OC6H2 (tBu)2)(μ-S) ((tBu)2C6H2O-)} X = Cl, F). Synthesis and transition metal complexes (molybdenum(0), ruthenium(II), palladium(II), and platinum(II)) of heterocyclic diphosphanes

Article abstract of DOI:10.1021/ic010518j

Bis(dichlorophosphino)aniline, PhN(PCl₂)₂, reacts with stoichiometric amounts of 2,2′-thiobis(4,6-di-tert-butylphenol) to afford a 10-membered heterocycle, PhN(PCl)₂{(-OC₆H₂ (^tBu)₂)μ-S) ((^tBu)₂C₆H₂O-)}(1), in high yield. The structure of the heterocycle has been determined by a single-crystal X-ray analysis. The 10-membered heterocycle 1 reacts with SbF₃ to afford the corresponding fluoro derivative 2 in good yield. The compounds 1 and 2 act as tridentate ligands with molybdenum carbonyl derivatives, forming complexes of the type [Mo(CO)₃-{η3-PhN(PX)₂ {(-OC₆H₂(^tBu)₂) (μ-S) ((^tBu)₂ C₆H₂O-)}-κP,κP,κS}] (3 X = Cl, Cl, 4 X = F). A crystal structure of the fluoro derivative 4 showed the facial tricarbonyl complex comprising a relatively strain-free tetracyclic structure with molybdenum in an octahedral environment; the two phosphorus and the sulfur centers were the donor atoms. Compound 2 readily reacts with Ru(II), Pd(II), and Pt(II) derivatives to form chelate complexes, demonstrating the η² mode of coordination.

Full text of DOI:10.1021/ic010518j

5620
Inorg. Chem. 2001, 40, 5620-5625
New 10-Membered Inorganic Heterocyclic Diphosphanes,
PhN(PX)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)} (X ) Cl, F). Synthesis and Transition
Metal Complexes (Molybdenum(0), Ruthenium(II), Palladium(II), and Platinum(II))
of Heterocyclic Diphosphanes. Crystal and Molecular Structures of the Chloro
Derivative, PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}, and of a
Molybdenum(0) Complex of the Fluoro Derivative,
[Mo(CO)3{η3-PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}-KP,KP,KS}]
Maravanji S. Balakrishna,*,† Rashmishree Panda,† and Joel T. Mague‡
Departments of Chemistry, Indian Institute of Technology,
Bombay, Powai, Mumbai 400 076, India, and Tulane University,
New Orleans, Louisiana 70118
ReceiVed May 16, 2001
Bis(dichlorophosphino)aniline, PhN(PCl2)2, reacts with stoichiometric amounts of 2,2′-thiobis(4,6-di-tert-
butylphenol) to afford a 10-membered heterocycle, PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)} (1), in high
yield. The structure of the heterocycle has been determined by a single-crystal X-ray analysis. The 10-membered
heterocycle 1 reacts with SbF3 to afford the corresponding fluoro derivative 2 in good yield. The compounds 1
and 2 act as tridentate ligands with molybdenum carbonyl derivatives, forming complexes of the type [Mo(CO)3-
{η3-PhN(PX)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}-κP,κP,κS}] (3 X ) Cl, 4 X ) F). A crystal structure of
the fluoro derivative 4 showed the facial tricarbonyl complex comprising a relatively strain-free tetracyclic structure
with molybdenum in an octahedral environment; the two phosphorus and the sulfur centers were the donor atoms.
Compound 2 readily reacts with Ru(II), Pd(II), and Pt(II) derivatives to form chelate complexes, demonstrating
the η2 mode of coordination.
Introduction
other pharmacological activities. The introduction of tervalent
phosphorus centers into the ring enhances the versatility of the
heterocycles in complexing with both hard and soft metals. Since
the tervalent phosphorus centers can stabilize transition metals
in low oxidation states, such complexes can be potential
homogeneous or phase-transfer catalysts in various organic
transformations. As a part of our interest10-16 and the interest
of others17-20 in designing new types of cyclic and acyclic
phosphorus-based ligands, we now report the synthesis of the
10-membered inorganic heterocycles with five heteroatoms
Heterocyclic ring systems containing trivalent phosphorus
atoms are distinguished from the open-chain phosphorus
compounds by some special characteristics not evident in the
latter.1-3 One of the most important features is the rigid
stereochemistry at the phosphorus centers in the ring. Also, it
is the ring substituents and the different functionalities at the
phosphorus centers that make the heterocycles fascinating with
respect to both structural and electronic properties. Heterocycles
with P-C, P-N, P-O, and P-S bonds, in addition to their
great biochemical and commercial importance,4 play a major
role in some substitution mechanisms as intermediates or as
transition states.5-7 Also, some phosphorus-containing hetero-
cycles have been found to be potentially carcinostatic8,9 among
(9) Gurusamy, N.; Berlin, K. D. J. Am. Chem. Soc. 1982, 104, 3114-
3119.
(10) Balakrishna, M. S.; Ramaswamy, K.; Abhyankar, R. M. J. Organomet.
Chem. 1998, 560, 131-136.
(11) Balakrishna, M. S.; Abhyankar, R. M.; Mague, J. T. J. Chem. Soc.,
Dalton Trans. 1999, 1407-1412.
* To whom correspondence should be addressed. Phone: (+91)-22-576-
7181. Fax: (+91)-22-572-3480. E-mail: krishna@iitb.ac.in.
† Indian Institute of Technology.
(12) Balakrishna, M. S.; Panda, R.; Smith, D. C., Jr.; Klaman, A.; Nolan,
S. P. J. Organomet. Chem. 2000, 599, 159-165.
(13) Balakrishna, M. S.; Teipel, S.; Pinkerton, A. A.; Cavell, R. G. Inorg.
Chem. 2001, 40, 1802-1808.
‡ Tulane University.
(1) Dimroth, K. Heterocyclic Rings Containing Phosphorus; Pergamon:
Elmsford, NY, 1984.
(14) Balakrishna, M. S.; Abhyankar, R. M.; Walawalker, M. G. Tetrahedron
Lett. 2001, 42, 2733-2734.
(2) Heal, H. G. The Inorganic Heterocyclic Chemistry of Sulfur, Nitrogen,
and Phosphorus; Academic Press: London, 1980.
(3) Caminade, A. M.; Majoral, J. P. Chem. ReV. 1994, 94, 1183-1213.
(4) Corbridge, D. E. C. Phosphorus: An Outline of its Chemistry,
Biochemistry, and Technology, 5th ed.; Elsevier: Amsterdam, 1995.
(5) Ramirez, F. Acc. Chem. Res. 1968, 1, 168-174.
(6) Westheimer, F. H. Acc. Chem. Res. 1968, 1, 70-78.
(7) Buchwald, S. L.; Pliura, D. H.; Knowles, J. R. J. Am. Chem. Soc.
1982, 104, 845-847.
(15) Balakrishna, M. S.; Walawalker, M. G. J. Organomet. Chem. 2001,
628, 76-80.
(16) Priya, S.; Balakrishna, M. S.; Mague, J. T. Inorg. Chem. Commun.
2001, 4, 437-440.
(17) Schranz, I.; Stahl, L.; Staples, R. J. Inorg. Chem. 1998, 37, 1493-
1498.
(18) Schranz, I.; Grocholl, L. P.; Stahl, L.; Staples, R. J.; Johnson, A. Inorg.
Chem. 2000, 39, 3037-3041.
(19) Kommana, P.; Kumara Swamy, K. C. Inorg. Chem. 2000, 39, 4384-
4385.
(8) Gurusamy, N.; Berlin, K. D.; Helm, V. D.; Hossain, M. B. J. Am.
Chem. Soc. 1982, 104, 3107-3114.
10.1021/ic010518j CCC: $20.00 © 2001 American Chemical Society
Published on Web 09/07/2001

Inorganic Heterocyclic Diphosphanes
Inorganic Chemistry, Vol. 40, No. 22, 2001 5621
Scheme 1
Table 1. Crystal Data for 1 and 4
in the ring, PhN(PX)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}
(1 X ) Cl, 2 X ) F), their spectroscopic characterization, and
the X-ray structure analysis of 1. Transition metal chemistry
of 1 and 2 is also described. Compound 1 retains the P-Cl
bond during the complex formation and exhibits η2 and η3
modes of coordination by utilizing a third donor atom such as
sulfur. The X-ray structure of a tricarbonyl molybdenum(0)
complex with the fluoro derivative acting as a tridentate li-
gand, [Mo(CO)3{η3-PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2-
O-)}-κP,κP,κS}], is also reported. The structure provides a rare
example of a phosphane heterocycle showing the flexible
tridentate (η3) coordination despite the presence of sterically
crowded substituents on the phosphorus centers.
1
4
formula
mol wt
a, Å
C34H45Cl2NO2P2S
664.61
9.8492(8)
C37H45F2MoNO5P2S
811.69
11.7037(7)
12.2971(5)
16.5033(8)
102.382(4)
98.894(5)
114.284(4)
2034.5(2)
2
b, Å
c, Å
17.6284(19)
21.2737(17)
R, °
â, °
102.918(6)
γ, °
V, Å3
3600.2(6)
4
Z
space group
temp, K
λ (Mo KR),a Å
P21/c (No. 14)
293
0.71073
1.226
P1h (No.2)
293
0.71073
1.325
0.5
0.0420
F
calcd, g cm-3
Results and Discussion
µ (Mo KR), cm-1
0.4
The stoichiometric reaction of bis(dichlorophosphino)ani-
line, Cl2PN(Ph)PCl2, with 2,2′-thiobis(4,6-di-tert-butylphenol)
in diethyl ether at ambient temperature afforded the thermo-
dynamically favored 10-membered heterocycle, PhN(PCl)2-
{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)} (1), in 89% yield
(Scheme 1).
Rb
0.0516
0.1268
0.076, 0.330
c
Rw2
0.1270
wgt par a, bc
0.07, 0.339
a Graphite monochromated. b R ) ∑|Fo - Fc|/∑Fo|. Rw2 ) [∑w(Fo
c
2
- Fc2)2/∑w(Fo )2 ]1/2; w ) 1/[σ2(Fo ) + (aP)2 + bP]; P ) 1/3[Fo2 + 2
Fc2].
2
2
The heterocyclic diphosphane 1 is a highly crystalline, white
solid that is soluble in dichloromethane, chloroform, toluene,
acetone, and acetonitrile and is moderately stable in air and in
moisture. The new 10-membered heterocycle represents the first
of its kind with five different elements and with coordinating
properties as well. The confirmation of the structure and
molecular composition of the heterocycle comes from NMR
spectroscopy (1H, 31P), high-resolution mass spectrometry, and
elemental analysis. The 31P NMR spectrum of 1 shows a single
resonance at 145.7 ppm indicating that the two phosphorus
centers are equivalent. The molecular structure is further
confirmed by X-ray crystallography.
Table 2. Selected Bond Distances (Å) and Bond Angles (deg) for
PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)} (1)
bond distances (Å)
bond angles (°)
P(1)-N
1.691(3)
1.718(3)
1.459(5)
2.067(19)
2.074(17)
1.773(4)
1.782(4)
1.636(3)
1.631(3)
1.398(5)
1.403(4)
1.403(5)
P(1)-N-P(2)
109.16(18)
127.6(3)
123.1(3)
126.9(2)
122.0(2)
104.12(15)
101.48(15)
103.12(13)
97.94(12)
95.29(12)
96.73(11)
101.02(18)
P(2)-N
P(1)-N-C(29)
P(2)-N-C(29)
P(1)-O(1)-C(1)
P(2)-O(2)-C(15)
O(1)-P(1)-N
N-C(29)
P(1)-Cl(1)
P(2)-Cl(2)
S-C(16)
S-C(6)
O(2)-P(2)-N
P(1)-O(1)
P(2)-O(2)
O(1)-C(1)
O(1)-C(15)
C(15)-C(16)
Cl(1)-P(1)-N
Cl(2)-P(2)-N
Cl(1)-P(1)-O(1)
Cl(2)-P(2)-O(2)
C(6)-S-C(16)
The structure of PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)} (1) with the atom numbering scheme is shown in
Figure 1. Crystal data and selected bond lengths and bond angles
are given in Tables 1 and 2, respectively. The structure consists
of a 10-membered ring puckered in a cuplike shape in such a
way that the lone pairs on the phosphorus centers and the two
chlorine atoms are remote from the bulky aryloxy groups. The
two chlorine atoms are mutually cis and are located on the same
side of the ring. The P(1)-N-P(2) bond angle of 109.15(18)°
is larger than the average P-N-P bond angles (97°-100°)
observed in cyclodiphosphazanes.21-24 The bond angles around
the nitrogen sum to 355.77°, indicating that the planar geometry
Figure 1. (a) Perspective view of 1 showing the atom numbering
scheme. Thermal ellipsoids are drawn at the 50% probability level and
hydrogen atoms are omitted for clarity. (b) View of the heterocyclic
ring displaying only the core atoms.
(20) Vijjulatha, M.; Kumaraswamy, S.; Kumara Swamy, K. C. Polyhedron
1999, 18, 2557-2562.
(21) Muir, K. W. J. Chem. Soc., Dalton Trans. 1975, 259-262.

5622 Inorganic Chemistry, Vol. 40, No. 22, 2001
Balakrishna et al.
Scheme 2
around the amine nitrogen is retained. The P(1)-N (1.691(3)
Å) bond is slightly shorter than the P(2)-N (1.718(3) Å) bond.
A single 31P NMR resonance in solution suggests that the
observed difference may result from packing or from other solid-
state effects. The average P-N bond length of 1.704(3) Å is
shorter than the normally accepted value for a single bond (1.77
Å),25 but it compares well with those found in a variety of
phosphorus(III)-nitrogen compounds26 suggesting a degree of
P-N multiple bonding. The P-O (mean) bond distance of
1.633(3) Å is larger than the average P-O bond distance of
1.600(6) Å observed in [{PhNP}2{-O(CH2)3O-}],23 while the
P‚‚P nonbonded separation is 2.778 Å.
The fluoro derivative shows phosphorus-fluorine couplings
similar to those in the free ligand. Further evidence for the
molecular composition of complexes 3 and 4 comes from the
elemental analysis, mass spectrometry, and the single-crystal
X-ray structure determination of the fluoro derivative 4.
The structure of the molybdenum complex, [Mo(CO)3{η3-
PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}-κP,κP,κS}] (4),
is confirmed by a single-crystal X-ray diffraction study. Crystal
data are given in Table 1, a perspective view of the molecule
with the numbering scheme is shown in Figure 2, and selected
bond lengths and bond angles are listed in Table 3. The structure
of 4 shows a monomeric chelated metal complex with a typical
octahedral metal environment in which the fluoro ligand acts
as a tridentate ligand via two tervalent phosphorus and one sulfur
centers in a facial orientation. The ligand is puckered in such a
way that the sulfur atom and one of the phosphorus centers
along with the two carbonyl groups occupy the equatorial
positions. The remaining carbonyl group and the other phos-
phorus center are in the axial positions. The S-Mo-P(2) and
S-Mo-P(1) bond angles are 81.66(4)° and 79.98(4)°, respec-
tively. There is no significant difference in the equatorial and
axial Mo-C bond lengths; the average Mo-C bond length is
2.004(2) Å. The mean P-N bond length is 1.690(3) Å. The
P(1)-N-P(2) bond angle (98.8°) is considerably smaller than
The reaction of cyclic phosphorochloridite 1 with SbF3
affords the fluoro derivative PhN(PF)2{(-OC6H2(tBu)2)(µ-S)-
((tBu)2C6H2O-)} (2) in good yield (Scheme 1). The identifica-
tion of the fluoro derivative 2 is based on mass spectrometry,
elemental analysis, and NMR spectroscopic data. The 31P NMR
spectrum of compound 2 consists of XAA′X′ doublets with
1
3
| JPF + JPF| ) 1153 Hz. The 31P NMR spectrum of 2 is best
interpreted as the A part of the XAA′X′ nuclear spin system27
with JXX′ ) 0.
The 10-membered heterocycles 1 and 2 with three potential
donor atoms (two tervalent phosphorus centers and a sulfur
center) can act as 2e- (η1), 4e- (η2 or µ), or 6e- (η3) donors
depending upon the metal reagents, the stoichiometry, and the
reaction conditions. The reactions of 1 and 2 with [Mo-
(CO)4NBD] in petroleum ether afford the tricarbonyl deriva-
tives, [Mo(CO)3{η3-PhN(PX)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)}-κP,κP,κS}] (3 X ) Cl, 4 X ) F), by the displace-
ment of a coordinated olefin and a carbonyl group with ligands
1 and 2, respectively, exhibiting a tridentate mode of coordina-
tion as shown in Scheme 2.
The infrared spectra of complexes 3 and 4 exhibit strong
absorptions in the range 1890-1987 cm-1 characteristic of
phosphine donors bound to [M(CO)3] moiety in the facial
conformation.28,29 The 31P NMR spectra of complexes 3 and 4
exhibit single resonances which are shielded compared to those
of the free ligands. The coordination shift is around 10 ppm.
(22) Chen, H. J.; Haltiwanger, R. C.; Hill, T. G.; Thompson, M. L.; Coons,
D. E.; Norman, A. D. Inorg. Chem. 1985, 24, 4725-4730.
(23) Kumaravel, S. S.; Krishnamurthy, S. S.; Cameron, T. S.; Linden, A.
Inorg. Chem. 1988, 27, 4546-4550.
(24) Kumaravel, S. S.; Krishnamurthy, S. S.; Cameron, T. S.; Linden, A.
Z. Naturforsch. B 1986, 41, 1067-1068.
(25) Pauling, L. The Nature of the Chemical Bond, 3rd ed.; Cornell
University Press: Ithaca, NY, 1960.
(26) Balakrishna, M. S.; Reddy, V. S.; Krishnamurthy, S. S.; Nixon, J. F.;
Burckett St. Laurent, J. C. T. R. Coord. Chem. ReV. 1994, 129, 1-90.
(27) Harris, R. K. Can. J. Chem. 1964, 42, 2275-2281.
(28) Brown, G. M.; Finholt, J. E.; King, R. B.; Lee, T. W. J. Am. Chem.
Soc. 1981, 103, 5249-5250.
Figure 2. (a) Perspective view of 4 showing the atom numbering
scheme. Thermal ellipsoids are drawn at the 50% probability level and
hydrogen atoms are omitted for clarity. (b) Plot of the central core of
4.
(29) King, R. B.; Lee, T. W. Inorg. Chem. 1982, 21, 319-324.

Inorganic Heterocyclic Diphosphanes
Inorganic Chemistry, Vol. 40, No. 22, 2001 5623
Scheme 3
The 31P NMR spectrum of palladium complex 6 exhibits a
single resonance at 74.5 ppm indicating the symmetric nature
of the molecule. The 31P NMR spectrum of the platinum(II)
analogue 7 also exhibits a single resonance at 46.7 ppm which
is considerably shielded, as expected, as compared to that of
the palladium(II) complex. Also, the platinum(II) complex 7
showed characteristic, very large, 1JPtP coupling of 4544 Hz that
is consistent with the proposed cis geometry.30,31
Table 3. Selected Bond Distances (Å) and Bond Angles (deg) for
[Mo(CO)3{η3-PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}-
κP,κP,κS}] (4)
bond distances (Å)
bond angles (°)
Mo-S
2.5242(1)
2.3770(12)
2.3653(12)
2.000(5)
1.9977(5)
2.015(5)
1.789(4)
1.808(4)
1.585(3)
1.568(3)
1.618(3)
1.617(3)
1.693(3)
1.682(3)
S-Mo-P(1)
79.98(4)
81.66(4)
91.3(2)
Mo-P(1)
Mo-P(2)
Mo-C(35)
Mo-C(36)
Mo-C(37)
S-C(2)
S-Mo-P(2)
C(36)-Mo-C(37)
C(35)-Mo-C(36)
P(1)-Mo-C(37)
P(2)-Mo-C(35)
S-Mo-C(37)
S-Mo-C(35)
S-Mo-C(36)
P(1)-Mo-C(35)
P(2)-Mo-C(37)
O(1)-P(1)-Mo
O(2)-P(2)-Mo
N-P(1)-Mo
N-P(2)-Mo
P(1)-N-P(2)
P(1)-N-C(29)
P(2)-N-C(29)
P(1)-Mo-P(2)
89.7(2)
101.50(14)
98.32(14)
89.18(14)
93.82(14)
176.41(15)
163.16(14)
165.09(14)
122.51(11)
119.89(11)
97.51(12)
98.28(12)
98.8(2)
Conclusion
S-C(20)
P(1)-F(1)
P(2)-F(2)
P(1)-O(1)
P(2)-O(2)
P(1)-N
Bis(dichlorophosphino)aniline, PhN(PCl2)2, with a PNP back-
bone reacts with 2,2′-thiobis(4,6-di-tert-butylphenol) to form a
heterocyclic phosphorochloridite with three potential soft donor
centers. The chloro derivative on treatment with SbF3 gives the
corresponding fluoro derivative in good yield. The new cyclo-
phosphanes readily form chelate complexes with the platinum
metals. Synthetic flexibility, easy synthetic methodology with
readily accessible nucleophilic sites, and the presence of three
potential donor atoms in this heterocycle are interesting.
P(2)-N
129.7(2)
131.4(2)
65.42(4)
either tetrahedral or trigonal angles, but the sum of the angles
around the nitrogen is 359.9° which clearly indicates that the
geometry around the nitrogen is planar. The decrease in the
P(1)-N-P(2) bond angle is a consequence of chelation.
The reaction of 1 with [RuCl2(PPh3)3] in a 2:1 ratio in CH2-
Cl2 solution affords an octahedral complex, trans-[Ru(Cl)2{η2-
PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}-κP,κP}2] (5),
in 93% yield (Scheme 3). The 31P NMR spectrum shows a single
resonance at 122.7 ppm, indicating that all of the PPh3 ligands
have been replaced by two phosphane heterocycles, with each
one acting as a bidentate chelating ligand. The 1H NMR
spectrum and the microanalysis of complex 5 agree well with
the proposed molecular composition. Treatment of [M(COD)-
Cl2] (M ) Pd or Pt) with 1:1 molar proportions of compound
1 in CH2Cl2 affords the chelate complexes 6 and 7 in good yield
(Scheme 3). In both of the complexes, the heterocyclic diphos-
phane ligand exhibits a chelating bidentate mode of coordination
via two phosphorus centers.
Experimental Section
All experimental manipulations were performed under an atmosphere
of dry nitrogen using Schlenk techniques.32 Solvents were dried and
distilled prior to use. 2,2′-Thiobis(4,6-di-tert-butylphenol),33 bis(dichlo-
rophosphino)aniline,34 [Mo(CO)4NBD],35 [RuCl2(PPh3)3],36 [Pd(COD)-
Cl2],37 and [Pt(COD)Cl2]38 were prepared according to the published
1
procedures. H and 31P{1H} NMR (δ in ppm) spectra were recorded
on a VXR 300S spectrometer (operating at the frequencies of 300 and
121 MHz respectively) using TMS and 85% H3PO4, respectively, as
external standards. CDCl3 was used both as a solvent and as an internal
(30) Balakrishna, M. S.; Klein, R.; Uhlenbrock, S.; Pinkerton, A. A.; Cavell,
R. G. Inorg. Chem. 1993, 32, 5676-5681.
(31) Balakrishna, M. S.; Santarsiero, B. D.; Cavell, R. G. Inorg. Chem.
1994, 33, 3079-3084.
(32) Shriver, D. F. The Manipulation of Air-SensitiVe Compounds; McGraw-
Hill: New York, 1969.
(33) Pastor, S. D.; Spivack, J. D.; Steinhuebel, L. P. J. Heterocycl. Chem.
1984, 21, 1285-1287.

5624 Inorganic Chemistry, Vol. 40, No. 22, 2001
Balakrishna et al.
lock. Positive shifts lie downfield of the standard in all of the cases.
Infrared spectra were recorded on a Nicolet Impact 400 FTIR instrument
in Nujol mull. Microanalyses were performed on a Carlo Erba model
1106 elemental analyzer. Melting points were recorded in capillary tubes
and are uncorrected.
in CH2Cl2 (8 mL) was added dropwise to a solution of [RuCl2(PPh3)3]
(0.048 g, 0.05 mmol) also in CH2Cl2 (8 mL). The reaction mixture
was stirred for 6 h at 25 °C, and then the solvent was removed under
reduced pressure to yield a pale yellow residue. Free PPh3 was removed
by extraction with several aliquots of Et2O to give an analytically pure,
yellow crystalline product of 5. Yield: 93% (0.07 g). Mp: 230 °C
(dec). Anal. Calcd for C68H90Cl6N2O4P4RuS2: C, 54.39; H, 6.04; N,
1.86. Found: C, 54.60; H, 6.07; N, 1.80. 1H NMR (300 MHz, CDCl3):
δ 7.32 (d, 2H, Ar), 7.08-7.18 (m, 5H, N-phenyl), 7.03 (d, 2H, Ar),
1.03 (s, 18H, tert-butyl), 1.18 (s, 18H, tert-butyl). 31P{1H} NMR
(121.421 MHz, CDCl3): δ 122.7(s).
Synthesis of [PdCl2{η2-PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)}-KP,KP}] (6). A CH2Cl2 (5 mL) solution of the ligand 1
(0.18 g, 0.27 mmol) was added dropwise to a solution of [Pd(COD)-
Cl2] (0.076 g, 0.27 mmol) also in CH2Cl2 (5 mL) at 25 °C. The reaction
mixture was stirred for 6 h to give a clear orange-yellow solution which
was concentrated to 3 mL and diluted with 1 mL of hexane. After the
solution was left to stand at room temperature, 6 formed as an
analytically pure, yellow crystalline product. Yield: 76% (0.17 g).
Mp: 140-142 °C. Anal. Calcd for C34H45Cl4NO2P2PdS: C, 48.50; H,
5.39; N, 1.66. Found: C, 48.32; H, 5.24; N, 1.59. 1H NMR (300 MHz,
CDCl3): δ 7.32 (d, 2H, Ar), 7.12-7.25 (m, 5H, N-phenyl), 7.08 (d,
2H, Ar), 1.05 (s, 18H, tert-butyl), 1.23 (s, 18H, tert-butyl). 31P{1H}
NMR (121.421 MHz, CDCl3): δ 74.5 (s).
Synthesis of PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)}
(1). A mixture of 2,2′-thiobis(4,6-di-tert-butylphenol) (6.9 g, 15.6 mmol)
and triethylamine (3.24 g, 32 mmol) in Et2O (150 mL) was added
dropwise to a suspension of bis(dichlorophosphino)aniline (4.6 g, 15.6
mmol) also in Et2O (100 mL) with vigorous stirring at 0 °C. The mixture
was stirred for 18 h at 25 °C. Triethylamine hydrochloride was removed
by filtration, and the solvent was removed under reduced pressure to
give a white crystalline product of 1 which was recrystallized from a
mixture of hexane/dichloromethane (1:1). Yield: 89% (9.24 g). Mp:
183 °C (dec). Anal. Calcd for C34H45Cl2NO2P2S: C, 61.52; H, 6.83;
N, 2.11. Found: C, 61.48; H, 6.78; N, 2.09. 1H NMR (300 MHz,
CDCl3): δ 7.35 (d, 2H, Ar), 7.11-7.21 (m, 5H, N-phenyl), 7.05(d,
2H, Ar), 1.13 (s, 18H, tert-butyl), 1.21 (s, 18H, tert-butyl). 31P{1H}
NMR (121.421 MHz, CDCl3): δ 145.7 (s). HRMS calcd for C34H45-
Cl2NO2P2S (M+), 663.2023; found, 663.1998.
Synthesis of PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2C6H2O-)} (2).
A mixture of 1 (2 g, 3.0 mmol) and SbF3 (1.34 g, 7.5 mmol) was heated
to reflux in n-heptane (100 mL) for 3 h. It was then cooled to room
temperature, filtered, and the filtrate was concentrated to 40 mL under
reduced pressure. Cooling this solution to 0 °C gave 2 as an analytically
pure, white crystalline solid. Yield: 84% (1.6 g). Mp: 180 °C (dec).
Anal. Calcd for C34H45F2NO2P2S: C, 64.63; H, 7.18; N, 2.21. Found:
Synthesis of [PtCl2{η2-PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)}-KP,KP}] (7). A CH2Cl2 (5 mL) solution of the ligand 1
(0.14 g, 0.21 mmol) was added dropwise to a solution of [Pt(COD)-
Cl2] (0.078 g, 0.21 mmol) also in CH2Cl2 (5 mL) at 25 °C. The reaction
mixture was stirred for 7 h to give a clear pale yellow solution. The
solution was concentrated to 3 mL, diluted with 1 mL of n-hexane,
and cooled to 0 °C whereupon an analytically pure sample of 7
precipitated out. Yield: 72% (0.14 g). Mp: 150-152 °C. Anal. Calcd
for C34H45Cl4NO2P2PtS: C, 43.90; H, 4.88; N, 1.50. Found: C, 43.80;
1
C, 64.54; H, 7.15; N, 2.19. H NMR (300 MHz, CDCl3): δ 7.41 (d,
2H, Ar), 7.15-7.25 (m, 5H, N-phenyl), 7.11 (d, 2H, Ar), 1.15 (s, 18H,
tert-butyl), 1.22 (s, 18H, tert-butyl). 31P{1H} NMR (121.421 MHz,
1
CDCl3): δ 134.7 (m), | JPF
+
3JPF| ) 1153 Hz. HRMS calcd for
C34H45F2NO2P2S (M+), 631.2614; found, 631.2591.
Synthesis of [Mo(CO)3{η3-PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)-
((tBu)2C6H2O-)}-KP,KP,KS}] (3). A petroleum ether (8 mL) solution
of [Mo(CO)4NBD] (0.087 g, 0.29 mmol) was added to a suspension
of 1 (0.193 g, 0.29 mmol) also in petroleum ether (10 mL). The mixture
was heated to 55 °C for 1.5 h to get a clear yellow solution which was
allowed to come to room temperature and then filtered. The filtrate
was concentrated to 5 mL and was cooled to -20 °C to give 3 as
analytically pure, yellowish-green crystals. Yield: 73% (0.18 g). Mp:
160 °C (dec). Anal. Calcd for C37H45Cl2MoNO5P2S: C, 52.62; H, 5.37;
N, 1.65. Found: C, 52.56; H, 5.33; N, 1.59. IR (Nujol, νCO, cm-1):
1
H, 4.81; N, 1.45. H NMR (300 MHz, CDCl3): δ 7.29 (d, 2H, Ar),
7.07-7.18 (m, 5H, N-phenyl), 7.03 (d, 2H, Ar), 1.01 (s, 18H, tert-
butyl), 1.23 (s, 18H, tert-butyl). 31P {1H} NMR (121.421 MHz,
1
CDCl3): δ 46.7(s), JPtP ) 4544 Hz.
X-ray Crystallography. Crystals of compounds 1 and 4 obtained
as described above were mounted on Pyrex filaments with epoxy resin.
General procedures for crystal alignment, unit cell determination, and
refinement and collection of data on the Enraf-Nonius CAD-4 diffrac-
tometer have been published,39 while details specific to the present study
are presented in Table 1. The raw intensity data were corrected for
Lorentz and polarization effects, for decreases in the intensities of the
monitor reflections,40 and, in the case of 4, for absorption using ψ
scans41 on several reflections with ø near 90°. For 1, the space group
was uniquely determined by the systematic absences observed in the
final data set, while for 4, the choice was made on the basis of intensity
statistics. Direct methods provided locations for a significant number
of atoms in 1, while the molybdenum atom in 4 was located from a
sharpened Patterson function. The completion and refinement of both
of the structures were accomplished with successive cycles of difference
Fourier syntheses followed by full-matrix, least-squares refinement. As
is evident in Figure 2a, two of the tert-butyl groups appear to suffer
from a degree of positional disorder, but this could not be satisfactorily
resolved into separate alternate locations for the methyl carbon atoms.
Hydrogen atoms were placed in calculated positions riding on the
attached carbon atoms with isotropic displacement parameters 20%
larger than those of the attached atom. All calculations associated with
structure solution and refinement were performed with the SHELXTL-
PLUS42 program package.
1
1982 s, 1912 s, 1895 s. H NMR (300 MHz, CDCl3): δ 7.32 (d, 2H,
Ar), 7.10-7.19 (m, 5H, N-phenyl), 7.02 (d, 2H, Ar), 1.14 (s, 18H,
tert-butyl), 1.20 (s, 18H, tert-butyl). 31P{1H} NMR (121.4 MHz,
CDCl3): δ 138.1 (s). MS (FAB, m/z) 844.
Synthesis of [Mo(CO)3{η3-PhN(PF)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)}-KP,KP,KS}] (4). A solution of [Mo(CO)4NBD] (0.087 g,
0.29 mmol) in petroleum ether (5 mL) was added dropwise to a
suspension of 2 (0.183 g, 0.29 mmol) also in petroleum ether (5 mL).
The mixture was heated to 50-55 °C for 1 h, after which the deep
brown solution was allowed to come to room temperature and was
then filtered. The filtrate was concentrated to 3 mL and when cooled
to -20 °C, it gave 4 as analytically pure, yellowish-green crystals.
Yield: 64% (0.15 g). Mp: 155 °C (dec). Anal. Calcd for C37H45F2-
MoNO5P2S: C, 54.75; H, 5.58; N, 1.72. Found: C, 54.63; H, 5.55; N,
1
1.69. IR (Nujol, νCO, cm-1): 1987 s, 1918 s, 1894 s. H NMR (300
MHz, CDCl3): δ 7.38 (d, 2H, Ar), 7.12-7.22 (m, 5H, N-phenyl), 7.09
(d, 2H, Ar), 1.11 (s, 18H, tert-butyl), 1.21 (s, 18H, tert-butyl). 31P-
1
{1H} NMR (121.421 MHz, CDCl3): δ 132.1 (m), | JPF + 3JPF| ) 1116
Hz. MS (FAB, m/z) 811.
Synthesis of [RuCl2{η2-PhN(PCl)2{(-OC6H2(tBu)2)(µ-S)((tBu)2-
C6H2O-)}-KP,KP}2] (5). A solution of the ligand 1 (0.067 g, 0.1 mmol)
Acknowledgment. We thank the Department of Science and
Technology (DST), New Delhi, for financial support of the work
(34) Davies, A. R.; Dronsfield, A. T.; Haszeldine, R. N.; Taylor, D. R. J.
Chem. Soc., Perkin Trans. 1 1973, 379-385.
(35) Bennett, M. A.; Pratt, L.; Wilkinson, G. J. Chem. Soc. 1961, 2037-
2044.
(39) Mague, J. T.; Lloyd, C. L. Organometallics 1988, 7, 983-993.
(40) Harms, K.; Wocadlo, S. Program to Extract Intensity Data from Enraf-
Nonius CAD-4 Files, University of Marburg, Germany, 1987.
(41) North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351-359.
(36) Hoffman, P. R.; Caulton, K. G. J. Am. Chem. Soc. 1975, 97, 4221-
4228.
(37) Drew, D.; Doyle, J. R. Inorg. Synth. 1972, 13, 52.
(38) Drew, D.; Doyle, J. R. Inorg. Synth. 1972, 13, 48.
(42) Bruker AXS. SHELXTL-PLUS, Version 5.1, Madison, WI, 1997.

Inorganic Heterocyclic Diphosphanes
Inorganic Chemistry, Vol. 40, No. 22, 2001 5625
Supporting Information Available: X-ray crystallographic files
in CIF format for the structure determination of PhN(PCl)2{(-OC6H2-
(tBu)2)(µ-S)((tBu)2C6H2O-)}(1) and [Mo(CO)3{η3-{PhN(PF)2{(-OC6H2-
(tBu)2)(µ-S)((tBu)2C6H2O-)}-κP,κP,κS}] (4). This material is available
free of charge via the Internet at http://pubs.acs.org.
done at the Indian Institute of Technology, Bombay, and we
thank the Chemistry Department, Tulane University, New
Orleans, LA, for the support of the crystallography laboratory.
We also thank the Regional Sophisticated Instrumentation center
(RSIC), Bombay, and Sophisticated Instrumentation Facility
(SIF), Bangalore, for NMR spectra.
IC010518J