Quest for organotin(IV) cations containing O,C,O-chelating ligands

Article abstract of DOI:10.1021/om049636f

A set of triorganotin(IV) compounds Ph₂L¹SnX and Ph₂L²SnX (1-9) with O,C,O-chelating ligands L¹ and L² (L¹ - 2,6-(MeOCH₂)₂C ₆H₃ and L² = 2,6-(t-BuOCH₂) ₂C₆H₃) containing different electronegative substituents X (X = I, CF₃COO, CF₃SO₃, PF ₆, and HgI₃) was prepared. These compounds have been characterized by elemental analysis, ESI-MS, and ¹H, ¹³C, and ¹¹⁹Sn NMR spectroscopy. X-ray diffraction analysis showed that the decrease of the nucleophilicity of X resulted in the formation of organotin cations stabilized by two strong Sn-O intramolecular interactions. In this transformation the ligand geometry about the tin atom changed from tetrahedral to trigonal bipyramidal with the OR groups in trans arrangement. Solution NMR studies indicated that the coordination geometry of these compounds is the same in the solid state and solution.

Full text of DOI:10.1021/om049636f

5300
Organometallics 2004, 23, 5300-5307
Qu est for Or ga n otin (IV) Ca tion s Con ta in in g
O,C,O-Ch ela tin g Liga n d s
Blanka Kasˇna´,† Roman J ambor,*,† Libor Dosta´l,† Alesˇ Ru˚zˇicˇka,†
Ivana C´ısarˇova´,‡ and J aroslav Holecˇek†
Department of General and Inorganic Chemistry, Faculty of Chemical Technology,
University of Pardubice, Cˇ s. legiı´ 565, CZ-532 10, Pardubice, Czech Republic, and Faculty of
Natural Science, Charles University in Prague, Hlavova 2030, 128 40 Praha 2, Czech Republic
Received May 21, 2004
A set of triorganotin(IV) compounds Ph2L1SnX and Ph2L2SnX (1-9) with O,C,O-chelating
ligands L1 and L2 (L1 ) 2,6-(MeOCH2)2C6H3 and L2 ) 2,6-(t-BuOCH2)2C6H3) containing
different electronegative substituents X (X ) I, CF3COO, CF3SO3, PF6, and HgI3) was
prepared. These compounds have been characterized by elemental analysis, ESI-MS, and
1H, 13C, and 119Sn NMR spectroscopy. X-ray diffraction analysis showed that the decrease of
the nucleophilicity of X resulted in the formation of organotin cations stabilized by two strong
Sn-O intramolecular interactions. In this transformation the ligand geometry about the
tin atom changed from tetrahedral to trigonal bipyramidal with the OR groups in trans
arrangement. Solution NMR studies indicated that the coordination geometry of these
compounds is the same in the solid state and solution.
Ch a r t 1
In tr od u ction
Despite the long history of the development of orga-
notin(IV) cations,1 which are belived to play an impor-
tant role in the cytotoxic activity of organotin com-
pounds2 or in catalytic applications involving organic
reactions such as esterification,3 only a limited number
of cationic compounds stabilized by donor atoms4 or free
stannylium cations5 have been isolated. The use of
Y,C,Y-chelating ligands in organotin compounds (Chart
1) is one of the possible entrees to the preparation of
organotin cations. J astrzebski et al. reported the use of
N,C,N-chelating ligand in the synthesis of air-stable
triorganotin cations6 (some of which were insoluble in
organic solvents)7 involving two strong Sn-N intra-
molecular interactions. J urkschat and co-workers pre-
pared triorganotin cations stabilized by two strong
Sn-O intramolecular interactions.8 Recently, we have
prepared organotin derivatives of O,C,O-chelating
ligands. However, triorganotin chlorides containing such
O,C,O-chelating ligands did not form organotin cations
containing two strong Sn-O interactions. The dissocia-
tion of the tin-chloride bond was not observed in this
case, in contrast to analogous triorganotin compounds
containing N,C,N-chelating ligands.9
This paper describes the synthesis of sets of triorga-
notin compounds containing O,C,O-chelating ligands L1
and L2 (where L1 ) 2,6-(MeOCH2)2C6H3 and L2 ) 2,6-
(t-BuOCH2)2C6H3; see Scheme 1). As the nucleophilic
character of the electronegative substituent X decreased
(Scheme 1), organotin cations stabilized by two Sn-O
intramolecular interactions were formed. Prepared com-
pounds enable us to study the effect of moderation of
* To whom correspondence should be addressed. Fax: + 420
466037068. E-mail: roman.jambor@upce.cz.
† University of Pardubice.
‡ Charles University in Prague.
(1) (a) Rochow, E. G.; Seyferth, D. J . Am. Chem. Soc. 1953, 75, 2877,
and references therein. (b) Okawara, R.; Rochow, E. G. J . Am. Chem.
Soc. 1960, 82, 3285. (c) McGrady, M. M.; Tobias, R. S. Inorg. Chem.
1964, 3, 1157. (d) Wada, M.; Okawara, R. J . Organomet. Chem. 1965,
4, 487. (e) Clark, H. C.; O’Brien, R. J . Inorg. Chem. 1965, 2, 740. (f)
Clark, H. C.; O’Brien, R. J .; Pickard, A. L. J . Organomet. Chem. 1965,
4, 43. (g) Wrackmeyer, B.; Kehr, C.; Boese, R. Angew. Chem., Int. Ed.
Engl. 1991, 30, 1370. (h) Wrackmeyer, B.; Kehr, G.; Sebald, A.;
Ku¨mmerlen, J . Chem. Ber. 1992, 125, 1597. For recent studies on
triorganotin cationic species in solution see: (i) Birchall, T.; Manivan-
nan, V. J . Chem. Soc., Dalton Trans. 1985, 2671. (j) Lambert, J . B.;
Kuhlmann, B. J . Chem. Soc., Chem. Commun. 1992, 931. (k) Lambert,
J . B.; Ciro, S. M.; Stern, C. L. J . Organomet. Chem. 1995, 499, 49.
(2) Pellerito, L.; Nagy, L. Coord. Chem. Rev. 2002, 224, 111.
(3) (a) Sakamoto, K.; Hamada, Y.; Akashi, H.; Orita, A.; Otera, J .
Organometallics 1999, 18, 3555. (b) Durand, S.; Sakamoto, K.; Fuku-
yama, T.; Orita, A.; Otera, J .; Duthie, A.; Dakternieks, D.; Schulte,
M.; J urkschat, K. Organometallics 2000, 19, 3220.
(6) J astrzebski, J . T. B. H.; van der Schaaf, P. A.; Boersma, J .; van
Koten, G.; de Wit, M.; Wang, Y. D.; Heijdenrijk, Y. D.; Stam, C. H. J .
Organomet. Chem. 1991, 407, 301.
(7) Ru˚zˇicˇka, A.; Dosta´l, L.; J ambor, R.; Buchta, V.; Brus, J .; Cı´sarˇova´,
I.; Holcˇapek, M.; Holecˇek, J . Appl. Organomet. Chem. 2002, 16, 315.
(8) Peveling, K.; Henn, M.; Lo¨w, C.; Mehring, M.; Schu¨rmann, M.;
Costisella B.; J urkschat, K. Organometallics 2004, 23, 1501.
(9) J ambor, R.; Dosta´l, L.; Ru˚zˇicˇka, A.; C´ısarˇova´, I.; Brus, J .;
Holcˇapek, M.; Holecˇek J . Organometallics 2002, 21, 3996
(4) Davies, A. G. Organotin Chemistry; Weinheim, 1997.
(5) (a) Lambert, J . B.; Zhao, Y. Angew. Chem., Int. Ed. Engl. 1997,
36, 400. (b) Kim, K.-C.; Reed, C. A.; Elliot, D. W.; Mueller, L. J .; Tham,
F.; Lin, L.; Lambert, J . B. Science 2002, 297, 825. (c) Lambert, J . B.;
Zhao, Y.; Wu, H.; Tse, W. C.; Kuhlmann J . Am. Chem. Soc. 1999, 121,
5001 (d) Zharov, I.; King, B. T.; Havlas, Z.; Pardi, A.; Michl J . J . Am.
Chem. Soc. 2000, 122, 10253. (e) Lambert, J . B.; Lin, L.; Keinan, S.;
Mu¨ller, T. J . Am. Chem. Soc. 2003, 125, 6022.
10.1021/om049636f CCC: $27.50 © 2004 American Chemical Society
Publication on Web 09/21/2004

Quest for Organotin(IV) Cations
Organometallics, Vol. 23, No. 22, 2004 5301
Sch em e 1: Nu m ber in g of P r ep a r ed Com p ou n d s
a n d La belin g of Atom s (for NMR solu tion on ly)
the Lewis acidity of the tin center on the magnitude of
the intramolecular tin-oxygen interactions and its
influence on the shape of tin coordination polyhedron.
The dependence of the Sn-O interaction strength on
increasing ligand spatial hindrance can be studied as
well.
F igu r e 1. General view (ORTEP) of a molecule of 1
showing 50% probability displacement ellipsoids and the
atom-numbering scheme. Only one molecule from the
crystal lattice of 1 without hydrogen atoms has been chosen
for clarity.
Resu lts a n d Discu ssion
Syn th etic Asp ects. Three synthetic methods were
used for preparation of the compounds studied. The
reaction of organotin compounds of type Ph3L1Sn with
I2 or Ph3L1Sn and Ph3L2Sn with Ph3C+PF6 gave the
-
temperatures than were needed in the case of the
L1-containing compounds.
corresponding organotin derivatives 1, 7, and 8 (eq 1).
However, the reaction of Ph3L2Sn with I2 under various
reaction conditions (elevated temperatures, different
solvents, and reaction time) did not lead to the expected
product, Ph2L2SnI. The product of this reaction was
identified as an adduct of Ph3L2Sn and I2 (2) (based on
1H, 13C, 119Sn NMR spectroscopy, electrospray ionization
mass spectrometry (ESI-MS), and elemental analysis;
see Experimental Section), a type of organotin com-
pounds for which, to the best of our knowledge, there is
no precedent.
The attempted use of the strong Lewis acid AlCl3 to
induce ionization of the Sn-Cl bond in the Ph2L1SnCl
and Ph2L2SnCl compounds was unsuccessful.11 How-
ever, the weaker Lewis acid (HgI2) did induce ionization
of the Sn-I bond of 1 to ionize, giving the organotin
cation with the triiodomercurate counterion (eq 3).
Molecu la r Str u ctu r es of 1, 3, 5, a n d 6. The
molecular structures of 1, 3, 5, and 6 are depicted in
Figures 1-4 (unit cells of compounds 1 and 6 consist of
two independent molecules). The crystallographic data,
selected bond lengths, and angles are given in Tables 1
and 2.
The shape of the tin coordination polyhedron is the
so-called “bicapped” tetrahedron in 1, and this com-
pound is an example of [4+2]-coordination, where a C3-
ISn tetrahedron is cis-attacked by two oxygen donor
atoms. The range of Sn-O bond lengths in 1 (Sn-O )
2.592(2)-2.991(2) Å) is substantially smaller than the
sum of the van der Waals radii of oxygen and tin atoms
(3.70 Å),12 but larger than the sum of the covalent radii
(2.066 Å),12 thus representing both weak and medium-
strong Sn-O interactions. The values of O(11)-Sn(1)-
O(12) bonding angles (117.50(6)° and 109.60(6)°) show
The conversion of triorganotin chlorides Ph2L1SnCl
and Ph2L2SnCl by reaction with the appropriate silver
salt, AgX, was the second procedure used for the
preparation of 3-6 (eq 2).
(10) Kost, D.; Kingston, V.; Gostevskii, B.; Ellern, A.; Stalke D.;
Walfort, B.; Kalikhman, I. Organomettalics 2002, 21, 2293.
(11) Similar results have been observed during the reaction of AlCl3
with organolithium compounds L1Li and L2Li.
In both procedures, the reaction of organotin com-
pounds with the sterically more hindered ligand L2
required the use of longer reaction times and higher
(12) Bondi, A. J . Phys. Chem. 1964, 68, 441.

5302 Organometallics, Vol. 23, No. 22, 2004
Kasˇna´ et al.
F igu r e 4. General view (ORTEP) of a molecule of 6
showing 50% probability displacement ellipsoids and the
atom-numbering scheme. Only one molecule from the
crystal lattice of 6 without hydrogen atoms has been chosen
for clarity.
F igu r e 2. General view (ORTEP) of a molecule of 3
showing 50% probability displacement ellipsoids and the
atom-numbering scheme. The hydrogen atoms are omitted
for clarity.
atom O(11) originates from the O,C,O-pincer ligand,
while the second one, O(1), is from the CF3COO- group.
The different values of the Sn(1)-O(1) (2.1546(13) Å)
and Sn(1)-O(2) (3.2096(15) Å) bond lengths clearly
indicate a monodentate bonding fashion of the CF3COO-
group to the central tin atom. The value of C(1)-O(2)
(1.215(2) Å) typical for the carbonyl part in the mono-
dentate carboxylic groups also proves this coordination
mode of the CF3COO- group.13 While the value of the
Sn(1)-O(11) bond length indicates a medium strength
interaction, the second oxygen donor atom from the
O,C,O-pincer ligand is bound weakly (Sn(1)-O(12) )
2.7940(15) Å).14 The value of the O(11)-Sn(1)-O(12)
bonding angle (117.24(4)°) shows that both oxygen donor
atoms of the O,C,O-chelating ligand are mutually in cis
positions.
Compounds 5 and 6 contain an organotin cation,
while the trifluoromethanesulfonate anion is out of the
primary tin coordination sphere (the nearest Sn(1)-O(3)
distance is 5.7446(18) Å for 5 and Sn(2)-O(6) is
6.978(3) Å for 6). The central tin atom is coordinated
by a carbon atom and two oxygen atoms from the ligand
L1 for 5 and L2 for 6 in a tridentate fashion and by two
carbon atoms from phenyl groups. The resulting geom-
etry is pseudo-trans-trigonal bipyramidal formed by
three carbon atoms in the equatorial plane and two
trans-oxygen atoms. The C3Sn girdle is almost planar
(∑C-Sn-C ) 359.79(7)° for 5 and 359.97(12)° for 6; for
comparison, the same parameter is 351.71(7)° for 3).
Nearly equivalent Sn-O bond distances (Sn(1)-O(11)
2.2724(14) Å, Sn(1)-O(12) 2.3013(15) Å in 5 and in the
range 2.3591(19)-2.391(2) Å in 6) indicate strong Sn-O
interactions in the cations and are comparable with
those found in diorganotin compounds (the range of
F igu r e 3. General view (ORTEP) of a molecule of 5
showing 50% probability displacement ellipsoids and the
atom-numbering scheme. The hydrogen atoms are omitted
for clarity.
the cis coordination of both oxygen donor atoms of the
O,C,O-chelating ligand. These oxygen atoms are bound
in pseudo-trans positions to I(1) and C(31) atoms,
resulting in the values of the C(31)-Sn(1)-I(1) bonding
angles of 93.81(7)° and 93.47(7)°, thus representing the
greatest deviations from the ideal tetrahedral shape.
The value of the Sn(1)-O(11) (2.4990(13) Å) bond
length indicates that the presence of the CF3COO-
group results in an increase of the Sn-O bond strength
in 3 in comparison to 1. The shape of the coordination
polyhedron is different: a trans-trigonal bipyramid
formed by three C atoms in the equatorial plane and
two oxygen donor atoms in axial positions (bonding
angle O(11)-Sn(1)-O(1) is 174.53(5)°). One oxygen
(13) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen
G.; Taylor, R. J . Chem. Soc., Perkin. Trans. 2 1987, 12, S1
(14) However, if this weak bond of Sn(1)-O(12) is taken in account,
then the geometry of 3 is an example of [5+1]-coordination where the
C3O2Sn trigonal bipyramid is attacked by the second oxygen donor
atom from the pincer ligand.

Quest for Organotin(IV) Cations
Organometallics, Vol. 23, No. 22, 2004 5303
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t 1, 3, 5, a n d 6
1
3
5
6
empirical formula
color
cryst syst
space group
a [Å]
C
22H23IO2Sn
C24H23F3O4Sn
colorless
C22H23O2Sn‚CF3O3S
colorless
triclinic
C28H35O2Sn‚CF3O3S
colorless
orthorhombic
Pna21 (No. 33)
20.8400(1)
yellow
orthorhombic
Pccn (No. 56)
25.1170(1)
25.6710(2)
13.0740(2)
monoclinic
P21/ n (No. 14)
10.4900(1)
11.5600(1)
18.8060(3)
P1h (No. 2)
8.6530(1)
10.7140(2)
13.0900(2)
94.9900(8)
99.4120(9)
101.1630(7)
2
b [Å]
C [Å]
18.0680(1)
15.9170(2)
R [deg]
â [deg]
γ [deg]
Z
90.4990(6)
16
2.690
1.781
4
8
µ [mm-1
]
1.173
1.605
1.242
1.673
0.976
1.488
Dx [Mg m-3
]
cryst size [mm]
cryst shape
0.3 × 0.17 × 0.13
0.35 × 0.2 × 0.2
0.50 × 0.0.3 × 0.2
0.38 × 0.2 × 0.15
bulk
prism
prism
prism
θ range, deg
1.0-27.5
0.600, 0.717a
141 938
9672, 0.048
8744
473
1.080
0.027
0.069
1.0-27.5
0.683, 0.727b
42 162
5237,0.037
4655
292
1.077
0.023
0.053
1.0-27.5
0.797, 0.855b
18 305
5310, 0.036
5014
301
1.042
0.022
0.055
1. 0-27.5
0.806, 0.864a
76 586
13 631; 0.044
12 487
715
0.995
0.028
0.067
T
min, Tmax
no. of reflns measd
no. of unique reflns; Rint
no. of obsd reflns [I > 2σ(I)]
no. of params
Sc all data
final Ra indices [I > 2σ(I)]
wR2a indices (all data)
d
w1/w2
0.0295/17.5166
0.0161/1.7470
0.0244/0.6254
0.0404/1.1718
-0.033(10)
0.471, - 0.774
absolute struct param
∆F, max., min. [e Å-3]
1.494, -1.313
0.816,-0.629
0.694,-0.714
a
b
2
Correction by SORTAV program. Correction by PLATON program. c Definitions: R(F) ) ∑||Fo| - ||Fc||/∑|Fo|, wR2 ) [∑(w(Fo
-
Fc2)2)/∑(w(Fo2)2]1/2, S ) [∑(w(Fo - Fc2)2)/(Nreflns - Nparams)]1/2
.
Weighting scheme w ) [σ2(Fo2) + (w1P) + w2P]-1. P ) [max(Fo2,0) +
2
d
2Fc2]/3. Rint ) ∑|Fo - Fo2(mean) |/∑Fo (summation is carried out only where more than one symmetry equivalent is averaged).
2
2
Ta ble 2. Selected Va lu es of Bon d in g Len gth s (Å) a n d An gles (d eg) for Com p ou n d s 1, 3, 5, a n d 6a
1(A)
1(B)
3
5
6(A)
6(B)
Sn1-C11
2.148(3)
2.136(3)
2.148(3)
2.641(2)
2.991(2)
121.92(10)
113.66(10)
110.62(11)
69.68(8)
86.83(8)
76.29(8)
66.76(9)
80.58(9)
163.46(9)
117.50(6)
2.139(3)
2.129(3)
2.151(3)
2.592(2)
2.906(2)
124.24(10)
114.14(10)
110.87(11)
69.72(9)
89.79(8)
77.97(8)
64.21(9)
76.48(9)
169.90(9)
109.60(6)
2.1302(19)
2.1384(18)
2.1196(17)
2.4990(13)
2.7940(15)
113.49(7)
124.18(7)
114.05(7)
71.67(6)
81.05(6)
88.58(6)
65.90(5)
158.30(6)
79.79(6)
2,0871(18)
2.1030(17)
2.1246(17)
2.2724(14)
2.3013(15)
127.61(7)
116.26(7)
115.93(7)
75.79(7)
100.47(6)
98.97(6)
74.89(7)
96.65(6)
94.66(6)
2.088(3)
2.110(2)
2.112(3)
2.3590(18)
2.3764(19)
121.10(11)
115.39(12)
123.48(12)
75.30(9)
96.45(8)
98.99(9)
74.98(9)
98.59(8)
93.85(9)
150.28(7)
2.091(2)
2.111(2)
2.115(3)
2.3704(19)
2.391(2)
119.24(11)
117.52(10)
123.15(11)
74.47(8)
95.36(10)
102.24(9)
74.47(8)
98.30(10)
93.41(9)
148.90(6)
Sn1-C21
Sn1-C31
Sn1-O11
Sn1-O12
C11-Sn1-C21
C11-Sn1-C31
C21-Sn1-C31
C11-Sn1-O11
C21-Sn1-O11
C31-Sn1-O11
C11-Sn1-O12
C21-Sn1-O12
C31-Sn1-O12
O11-Sn1-O12
117.24(4)
150.67(5)
a
Two independent molecules (A, B) have been found in the unit cells of 1 and 6.
Sn-O is 2.203-2.278 Å)15 and in organotin cations
(Sn-O distances 2.249(2) and 2.241(3) Å)8 containing
different types of O,C,O-chelating ligands (aryldiphos-
phonic ester C6H2[P(O)(OEt)2]2-1,3-t-Bu-5). Since both
oxygen atoms are part of one tridentate O,C,O-chelating
ligand, the main deformation from the ideal trigonal
bipyramidal geometry is seen for the O(11)-Sn(1)-
O(12) angle (150.67(5)° for 5 and 150.28(7)° for 6).
Comparable deviations in pseudo-trans-trigonal bipy-
ramidal structures have also been found in other
triorganotin cations bearing both N,C,N- (C6H3-
(CH2NMe2)2-, range of N-Sn-N bonding angles is
150.7-152.7°)6,7,16 and O,C,O-chelating ligands (C6H2-
[P(O)(OEt)2]2-1,3-t-Bu-5, O-Sn-O ) 159.01(9)°).8 Com-
parison of compounds 5 and 6 shows that the Sn-O
donor-acceptor bond is somewhat weaker in 6 than in
5, as the result of steric hindrance of ligand L2.
The shapes of coordination polyhedra of 1, 3, and 5
form a natural transformation from tetrahedron to
trigonal bipyramid going from 1 to 5. The strength of
the Sn-O intramolecular interaction seems to be a
particular factor for establishing the shape of the tin
coordination geometry in these compounds. The forcing
of the Sn-O bond thus leads to a shift toward trigonal
bipyramid, and one of the possible indicators of this
transformation is the sum of all bonding angles C-Sn-C
(328.5° in an ideal tetrahedron and 360° in an ideal
trigonal bipyramid). The value of this parameter being
349° in 1 indicates that the shape of the tin coordination
polyhedron is shifted to tetrahedron in 1, while the
value 359.8° establishes the trigonal bipyramidal ge-
ometry in 5. The values of the bonding angle O(11)-
(15) (a) Mehring, M.; Schu¨rmann, M.; J urkschat, K. Organometallics
1998, 17, 1227. (b) Mehring, M.; Vrasidas, I.; Horn, D.; Schu¨rmann,
M.; J urkschat, K. Organometallics 2001, 20, 4647. (c) Mehring, M.;
Lo¨w, Ch.; Uhlig, F.; Schu¨rmann, M.; J urkschat, K.; Mahieu, B.
Organometallics 2000, 19, 4613.
(16) (a) Amini, M. M.; Heeg, M. J .; Taylor, R. W.; Zuckerman, J . J .;
Ng, S. W. Main Group Met. Chem. 1993, 16, 415. (b) J ambor, R.;
C´ısarˇova´, I.; Ru˚zˇicˇka, A.; Holecˇek, J . Acta Crystallogr. 2001, C57, 373.

5304 Organometallics, Vol. 23, No. 22, 2004
Ta ble 3. Selected 1H, 13C, a n d 119Sn NMR Da ta a for 1-8
Kasˇna´ et al.
δ(119Sn)iso
δ(119Sn)
[ppm]
δ(1H(CH2))
[ppm]
δ(13C(1)) [ppm]
δ(13C(1′)) [ppm]
compound
[ppm]b
(nJ (119Sn, 13C)[Hz])
(nJ (119Sn, 13C)[Hz])
1
2
3
4
5
6
7
8
-204.7
-113.3
-179.8
-152.7
-33.5
-25.8
c
4.5
4.4
4.5
4.6
5.1
4.9
c
133.8 (555.7)
134.7c
136.3 (535.2)
136.5 (565.9)
140.6 (774.5)
141.6 (776.2)
134.4 (752.9)
139.9 (742.6)
c
-199.2
-172.5
-25.7
-17.5
-26.8
-19.5
134.6 (786.4)
132.6 (738.8)
123.6 (776.2)
119.7 (760.1)
c
c
c
c
c
a
b
Measured in CDCl3. 119Sn CP/MAS was measured only for compounds 3-8. c Not found.
Ta ble 4. Tem p er a tu r e Dep en d en ce of Selected 1H NMR P a r a m eter s [p p m ] (r a n ge 170-300 K for tolu en e-d 8
a n d m eth a n ol-d 4 a n d 190-300 K for ch lor ofor m -d 1)
toluene-d8 (for 3, 4) or
chloroform-d1 (for 5, 6, 9)b
methanol-d4
compound
Ta [K]
CH3
2.57
2.83/1.99
0.76
1.01/0.98
3.65
3.35
1.05
1.00
3.56
3.60
CH2OR
CH3
CH2OR
3
300
170
300
170
300
190
300
190
300
190
4.07
4.24/3.43
4.49
4.87/4.03
5.08
4.95
4.87
4.75
5.02
5.03
2.96
4.55
2.93/2.77
0.99
4.45/4.40
4.75
4
5
6
9
1.01
3.35
2.87
1.16
4.67
4.90
4.67
4.87
1.14;1.02/1.00c,d
5.11;4.59/4.57c,d
a
b
The temperature range 300-190 K has been measured in chloroform-d1. Explained in text. c New signal observed at 230 K.
d
Decoalescence at 190 K.
1
1
Sn(1)-O(12) of 117.50(6)° for 1, 117.24(4)° for 3, and
150.67(5) for 5 indicate a transformation of both oxygen
donor atoms’ coordination mode from cis to trans.
Solu tion a n d CP /MAS NMR Stu d ies. It is well
known that the 119Sn NMR shifts and 1J (119Sn, 13C)
coupling constants are sensitive indicators for elucida-
tion of the coordination numbers and geometries of
the J (119Sn, 13C(1)) and J (119Sn,13C(1′)) coupling con-
stant values, the increased strength of the Sn-O
interaction in 3 and 4. The magnitudes of the calculated
bond angles C(1)-Sn-C(1′) and C(1′)-Sn-C(1′) (122.6°,
121.8° for 3 and 119.7°, 121.9° for 4) indicate trans-
trigonal bipyramidal geometry similar to the molecular
structure of 3. To prove the nonequivalence of both
ortho-CH2OR substituents and to see if the ionic species
is not formed at a lower temperature or in a polar
solvent, the dynamic behavior of 3 and 4 was studied
by 1H NMR spectroscopy at various temperatures (range
300-170 K) in both toluene-d8 and methanol-d4 solu-
tion.10,19
1
organotin compounds, but H NMR shifts of methylene
protons also gave suitable information about the Sn-O
interaction strength (downfield shift going from covalent
to ionic species). None of the studied compounds exhibit
any concentration dependences of the 119Sn NMR shifts,
and the values of δ(119Sn)iso are similar to the values of
the 119Sn NMR shifts in solution (see Table 3), indicating
no intermolecular interactions are present in solution
and in the solid state.
At room temperature, the 1H NMR spectrum displays
one set of sharp signals for all the protons. As the
temperature decreased, first a broadening of the CH2
and CH3 protons was observed, followed by decoales-
cence of all the protons at 260 K for 3, 200 K for 4 in
toluene-d8, and 185 K for 3 in methanol-d4 (no decoa-
lescence was observed for 4 in methanol-d4; see Table
4). This indicates the well-known dissociation/associa-
tion dynamic procedure20 resulting in nonequivalence
of both CH2OR “arms” in 3 and 4, similar to the
molecular structure of 3. The energy barriers (∆Gq)21
of the fluxional processes are 47.8 kJ mol-1 (3) and 36.1
kJ mol-1 (4) in toluene and 37.6 kJ mol-1 (3) in
methanol-d4, respectively. This clearly shows the dif-
ferent strength of the Sn-O bond both in 3 and 4 (steric
factor of L2) and in nonpolar and polar solvents.
The value of δ(119Sn) ) -204.7 ppm in 1 (see Table
3) does not correspond to a stronger Sn-O interaction
and a higher coordination number of the tin atom than
in analogous triorganotin chloride Ph2L1SnCl (δ(119Sn)
) -144.4 ppm), but it can be the result of the different
halide present (compare the values of δ(119Sn) in Ph3-
SnCl (-44.7 ppm) and Ph3SnI (-112.8 ppm)).17 The
1
other NMR parameters (1J (119Sn, 13C(1)), J (119Sn,13C-
(1′)) and magnitudes of the calculated bond angles C(1)-
Sn-C(1′) and C(1′)-Sn-C(1′)18 (108.2°, 106.9°) estab-
lished a similar shape of tin atom coordination polyhedra
in 1 going from the solid state to solution.
In compounds 3 and 4, the values of δ(119Sn) (see
Table 3) are shifted upfield compared to the correspond-
ing chlorides Ph2L1SnCl (-144.4 ppm) and Ph2L2SnCl
(-121.7 ppm), reflecting, together with an increase of
(19) Ru˚zˇicˇka, A.; J ambor, R.; C´ısarˇova´, I.; Holecˇek, J . Chem. Eur.
J . 2003, 9, 2411.
(20) Handwerker, H.; Leis, C.; Probst, R.; Bassinger, P.; Grohmann,
A.; Kiprof, P.; Herdtweek, F.; Blu¨mel, J .; Auner, N.; Zybill, C.
Organometallics 1993, 12, 2162.
(17) Holecˇek, J .; Na´dvorn´ık, M.; Handl´ırˇ, K.; Lycˇka, A. J . Orga-
nomet. Chem. 1983, 241, 177.
(18) Holecˇek, J .; Na´dvorn´ık, M.; Handl´ırˇ, K.; Lycˇka, A. Z. Chem.
1990, 30, 265.
(21) Eyring equation: ∆Gq) -RTc ln [2πh(∆υ)/kTcx3] with ∆Gq
)
free energy of activation (J ), Tc ) coalescence temperature (K), and
∆υ ) chemical shift difference (Hz); the other symbols have their usual
meanings.

Quest for Organotin(IV) Cations
Organometallics, Vol. 23, No. 22, 2004 5305
species ∆Gq of the dissociation/association dynamic
procedure is 40.2 kJ mol-1). The coordination of metha-
nol to the central tin atom seems to be the best
explanation for this observation.
The methanol molecules probably start to coordinate
the organotin cation resulting in the new species at 230
K, and its concentration is increased during the tem-
perature decrease (see Figure 5, equilibrium of nonco-
ordinated (A) and coordinated (B) form of organotin
cation 6). The equilibrium constants K ) [B]/[A] were
F igu r e 5. Equilibrium between the noncoordinated (A)
and coordinated (B) form of organotin cation 6.
One narrow signal (δ(119Sn) ) -33.5 ppm for 5 and
-25.8 ppm for 6) was observed in the 119Sn NMR spectra
1
evaluated directly from H NMR spectra of 6 below 230
K, when the signals for both species were observed. The
K values for A T B equilibrium have been evaluated at
a number of temperatures and used for a ln K vs T-1
plot (Figure 6), and from the linear relation the reaction
enthalpy and entropy have been extracted: ∆H° )
of 5 and 6. These significant downfield shifts of δ(119
-
Sn) (∆δ(119Sn) ) -110.9 ppm for 5 and -95.9 ppm for
6) going from Ph2L1SnCl and Ph2L2SnCl to 5 and 6
indicate their coordination mode and the presence of
organotin cations.22 Other NMR parameters (1J -
-17.5 kJ mol-1, ∆S° ) -89.7 J mol-1 K-1
.
(
119Sn,13C) and the downfield shift of δ(1H(CH2)) of about
Compounds 7 and 8 are insoluble in common organic
solvents and could not be investigated by NMR spec-
troscopy. IR study of these compounds has shown the
presence of characteristic bands ν(P-F) at 878, 341 cm-1
for 7 and 878, 342 cm-1 for 8, which are typical for
inorganic ionic compounds containing the PF6- group.23
Also 119Sn CP/MAS NMR study has proved the ionic
character of 7 and 8, because the obtained values of δ-
0.5 ppm (see Table 3)) established an important increase
of Sn-O bond strength in 5 and 6 compared to Ph2L1-
SnCl and Ph2L2SnCl. The values of the C(1)-Sn-C(1′)
and C(1′)-Sn-C(1′) bonding angles (122°, 121° for 5 and
120°, 121° for 6) define the trans-trigonal bipyramidal
geometry of these organotin cation containing O,C,O-
chelating ligands, similar to those found in the solid
state for 5 and 6.
(
119Sn)iso are comparable with 5 and 6 (see Table 3). Also
1
The various temperatures of H NMR spectroscopy
1
9 is poorly soluble in common organic solvents, but H
NMR spectroscopy in chloroform-d1 (range 300-190 K)
gives information about the ionic character of 9 (the
downfield shift of δ(1H(CH2)) and no decoalescence of
any protons at low temperate was observed similarly
to 6; see Table 4).
both in chloroform-d1 (range 300-190 K) and in methanol-
d4 (range 300-170 K, 5 and 6 are insoluble in toluene)
solution of 5 and 6 also proved the equivalence of both
CH2OR groups, being strongly coordinated to the tin
atom through the Sn-O bond, and no decoalescence of
any protons has been observed in chloroform-d1 (5 and
6) and in methanol-d4 (5).
However, in methanol-d4 solution of 6, the second set
of aliphatic signals (in addition to the previous one
observed at 300 K, see Table 4) was observed on
decreasing the temperature to 230 K (approximately 5%
of main peaks’ intensity), and these signal intensities
were increased with the decrease of temperature. Other
temperature lowering resulted in the broadening of
these new CH2 and CH3 protons followed by decoales-
cence of these proton signals at 190 K (see Table 4,
nonequivalence of both CH2OR groups in this new
Exp er im en ta l Section
Gen er a l Meth od s. Solvents were dried by standard meth-
ods and distilled prior to use. All moisture- and air-sensitive
reactions were carried out in an argon atmosphere using
standard Schlenk techniques. The reactions with silver salts
1
were protected from light. The H,13C, and119Sn NMR spectra
were acquired on Bruker AMX360 or Avance500 spectrometers
at 300 K in CDCl3 or in toluene-d8 and methanol-d4 for
temperatures in the range 300-170 K. Appropriate chemical
1
shifts were calibrated on the H residual peak of CHCl3 (δ )
F igu r e 6. Plot of ln K vs 1/T for the equilibrium reaction of 6 with CD3OD.

5306 Organometallics, Vol. 23, No. 22, 2004
Kasˇna´ et al.
7.25 ppm), toluene (δ ) 2.09 ppm), and methanol (δ ) 3.31
ppm), the 13C residual peak of CHCl3 (δ ) 77.00 ppm), and
119Sn external tetramethylstannane (δ ) 0.00 ppm). Chemical
shift data are provided in ppm, with coupling constants in Hz.
Abbreviations used are as follows: s ) singlet; q ) quartet; m
) complex multiplet. Solid-state 119Sn spectra were recorded
on a Bruker DSX 200 spectrometer equipped with a double-
bearing CP/MAS probe at room temperature. The 119Sn Hart-
man-Hahn cross-polarization match was set with tetracyclo-
25 °C, the solid residue was filtered off, and the solvent was
evaporated in vacuo. The residue was washed with pentane.
Recrystallization of the residue from a CHCl3/pentane solution
(1:1) led to 3 as a white solid. Yield: 0.052 g (78%); mp 120-
123 °C. Anal. Calcd for C24H23F3O4Sn (MW 551.13): C, 52.30;
H, 4.21. Found: C, 52.15; H, 4.19. MS: m/z 385, 33%, [3 ×
CF3COO + 2 × Na]-; m/z 249, 73%, [2 × CF3COO + Na]-;
m/z 113, 100%, [CF3COO]-; m/z 439, 100%, [M - CF3COO]+.
1H NMR (CDCl3, 360 MHz): δ (ppm) 2.97 (s, 6H, CH3), 4.52
(s, 4H, CH2, nJ (119Sn,1H) ) 7.9 Hz), 7.20-7.90 (complex
pattern, 13H, SnPh2, SnC6H3). 13C NMR (CDCl3, 90 MHz):
1
hexyl tin using a H 90° pulse of 4 µs. RAMP/CP/MAS (ramped/
cross-polarization/magic angle spinning) experiments were
used with a repetition delay of 10 s, and the contact time was
set at 2 ms. In each case, at least two spinning rates (4.5-10
kHz) were used to identify the isotropic chemical shift. The
number of scans varied between 500 and 1024. The 119Sn
chemical shifts were calibrated indirectly using tetracyclohexyl
tin (δ -97.35 ppm). The 119Sn NMR chemical shift was
allocated approximately to the center of gravity of the signal.
Electrospray mass spectra (ESI/MS) were recorded in positive
mode on an Esquire3000 ion trap analyzer (Bruker Daltonics)
in the range 100-600 m/z and in the negative mode on the
Platform quadrupole analyzer in the range 100-800 m/z. The
samples were dissolved in acetonitrile and analyzed by direct
n
57.8 (CH3), 74.5 (CH2, J (119Sn,13C) ) 22.2 Hz), 114.4 (q-CF3,
nJ (19F,13C) ) 289.2 Hz), 160.3 (COO); SnC6H3, 134.6 (C(1),
1J (119Sn,13C) ) 786.4 Hz), 145.8, 126.4, 136.2; SnPh2, 140.6
(C(1′), 1J (119Sn,13C) ) 774.5 Hz), 136.1, 128.6, 129.5. IR
(suspension in Nujol): νas(CO) 1699 cm-1, νs(CO) 1456 cm-1
;
(solution in CHCl3) νas(CO) 1709 cm-1, νs(CO) 1455 cm-1
.
Syn t h esis of [2,6-Bis(ter t-b u t oxym et h yl)p h en yl]d i-
p h en yltin Tr iflu or oa ceta te [4]. CF3COOAg (0.03 g, 0.12
mmol) was added to a stirred solution of Ph2L2SnCl (0.06 g,
0.1 mmol) in CH2Cl2 (10 mL). The suspension was stirred for
7 days at 25 °C, the solid was filtered off, and the solvent was
evaporated in vacuo. The residue was washed with pentane
to provide 4 as a brownish solid. Yield: 0.052 g (75%); mp 161-
164 °C. Anal. Calcd for C30H35F3O4Sn (MW 635.30): C, 56.72;
H, 5.55. Found: C, 56.70; H, 5.56. MS: m/z 749, 100%, [M +
CF3COO]-; m/z 521, 70%, [4 × CF3COO + 3 × Na]-; m/z 385,
51%, [3 × CF3COO + 2 × Na]-; m/z 249, 33%, [2 × CF3COO
+ Na]-; m/z 113, 15%, [CF3COO]-; m/z 523, 100%, [M - CF3-
COO]+. 1H NMR (CDCl3, 360 MHz): δ (ppm) 0.91 (s, 18H,
CH3), 4.64 (s, 4H, CH2, nJ (119Sn,1H) ) 7.2 Hz)), 7.41-7.95
(complex pattern, 13H, SnPh2, SnC6H3). 13C NMR (CDCl3, 90
MHz): δ (ppm) 27.1 (CH3), 65.3 (CH2, nJ (119Sn,13C) ) 23.3 Hz),
76.5 (OCMe3), 119.0 (q-CF3, nJ (19F,13C) ) 289.2 Hz) 160.3
infusion at a flow rate of 1-10 µL/min. The IR spectra (cm-1
)
were recorded on Perkin-Elmer 684 equipment as Nujol
suspensions or CHCl3 solutions (except 7 and 8). Starting
compounds Ph3L1Sn, Ph3L2Sn, Ph2L1SnCl, and Ph2L2SnCl
were prepared according to the literature.9
Syn th esis of [2,6-Bis(m eth oxym eth yl)p h en yl]d ip h en -
yltin iod id e [1]. Iodine (0.1 g, 0.4 mmol) in CH2Cl2 (10 mL)
was added dropwise to a stirred solution of Ph3L1Sn (0.2 g,
0.4 mmol) in CH2Cl2 (10 mL). The mixture was stirred for 2
days at 25 °C. The solvent was evaporated in vacuo, and the
residue was washed with pentane to give 1 as a yellow solid.
Yield: 0.15 g (70%); mp 115-118 °C. Anal. Calcd for C22H23
-
1
(COO); SnC6H3, 132.6 (C(1), J (119Sn,13C) ) 738.8 Hz), 147.4,
IO2Sn (MW 565.02): C, 46.77; H, 4.10. Found: C, 46.67; H,
4.11. MS: m/z 127, 100%, [I]-; m/z 439, 100%, [M - I]+. 1H
NMR (CDCl3, 360 MHz): δ (ppm) 2.86 (s, 6H, CH3), 4.47 (s,
126.3, 130.0; SnPh2, 141.6 (C(1′), 1J (119Sn,13C) ) 776.2 Hz),
136.2, 128.6, 129.8. IR (suspension in Nujol): νas(CO) 1705
cm-1, νs(CO) 1456 cm-1; (solution in CHCl3) νas(CO) 1709 cm-1
,
n
4H, CH2, J (119Sn,1H) ) 7.6 Hz), 7.30-7.80 (complex pattern,
νs(CO) 1455 cm-1
Syn t h esis of
.
13H, SnPh2, SnC6H3). 13C NMR (CDCl3, 90 MHz): 57.4 (CH3),
73.6 (CH2, nJ (119Sn,13C) ) 23.8 Hz), SnC6H3, 133.8 (C(1),
1J (119Sn,13C) ) 555.7 Hz), 125.5, 127.5, 144.8; SnPh2, 141.5
[2,6-Bis(m et h oxym et h yl)p h en yl]d i-
p h en yltin Tr iflu or om eth a n su lfon a te [5]. A procedure
similar to that for 3 was used. Reaction of Ph2L1SnCl (0.1 g,
0.2 mmol) and CF3SO3Ag (0.06 g, 0.3 mmol) resulted in 5.
Yield: 0.095 g (70%); mp 164-170 °C. Anal. Calcd for
1
(C(1′), J (119Sn,13C) ) 535.2 Hz), 126.9, 133.9, 127.5.
Syn th esis of th e Ad d u ct of [2,6-Bis(ter t-bu toxym eth -
yl)p h en yl]tr ip h en yltin w ith Iod in e [2]. Iodine (0.09 g, 0.4
mmol) in CH2Cl2 (10 mL) was added dropwise to a stirred
solution of Ph3L2Sn (0.2 g, 0.4 mmol) in CH2Cl2 (10 mL). The
mixture was stirred for 2 days at 25 °C, and the solvent was
evaporated in vacuo. The residue was washed with pentane
to provide a yellow solid. Recrystallization of the residue from
CH2Cl2/pentane led to 2. Yield: 0.28 g (85%); mp 99-102 °C.
Anal. Calcd for C34H40I2O2Sn (MW 837.15): C, 47.80; H, 4.73.
Found: C, 46.80; H, 4.48. MS: m/z 127, 100%, [I]-; m/z 380,
12%, [I3]-; m/z 411, 100%, [M - I - 2 × isobutene]+; m/z 467,
65%, [M - I - isobutene]+; m/z 523, 53%, [M - I2 - C6H6]+;
351, 5%, [M - I - 2 × isobutene - C6H6 + H2O]+. 1H NMR
(CDCl3, 360 MHz): δ (ppm) 1.31 (s, 18H, CH3), 4.44 (s, 4H,
CH2), 7.40-7.75 (complex pattern, 18H, SnPh2, SnC6H3). 13C
NMR (CDCl3, 90 MHz): 27.7 (CH3), 65.8 (CH2), 73.7 (OCMe3);
SnC6H3, 134.7 (C(1)), 127.2, 128.8, 141.8; SnPh2, 136.5 (C(1′),
1J (119Sn,13C) ) 565.9 Hz), 129.0, 136.3, 130.2.
C
23H23F3O5SSn (MW 587.19): C, 47.05; H, 3.95. Found: C,
46.71; H, 3.90. MS: m/z 321, 46%, [2 (0.06 g, 0.3 mmol) CF3-
SO3 + Na]-; m/z 149, 100%, [CF3SO3]-; m/z 439, 100%, [M -
1
CF3COO]+. H NMR (CDCl3, 360 MHz): δ (ppm) 3.65 (s, 6H,
CH3), 5.08 (s, 4H, CH2, nJ (119Sn,1H) ) 8.5 Hz), 7.35-7.70
(complex pattern, 13H, SnPh2, SnC6H3). 13C NMR (CDCl3, 90
MHz): δ (ppm) 60.4 (CH3), 74.9 (CH2, nJ (119Sn,13C) ) 21.8 Hz),
120.48 (q-CF3, nJ (19F,13C) ) 320.4 Hz), SnC6H3, 123.6 (C(1),
1J (119Sn,13C) ) 738.8 Hz), 142.5, 124.2, 134.7; SnPh2, 134.4
(C(1′), 1J (119Sn,13C) ) 752.9 Hz), 136.0, 130.1, 132.1. IR
(suspension in Nujol): νas(SO3) 1260 cm-1; (solution in CHCl3)
νas(SO3) 1262 cm-1
.
Syn t h esis of [2,6-Bis(ter t-b u t oxym et h yl)p h en yl]d i-
p h en yltin Tr iflu or om eth a n su lfon a te [6]. A procedure
similar to that for 4 was used. Reaction of Ph2L2SnCl (0.1 g,
0.2 mmol) and CF3SO3Ag (0.06 g, 0.2 mmol) resulted in 6.
Yield: 0.099 g (70%); mp 146-150 °C. Anal. Calcd for
Syn th esis of [2,6-Bis(m eth oxym eth yl)p h en yl]d ip h en -
yltin Tr iflu or oa ceta te [3]. CF3COOAg (0.04 g, 0.2 mmol)
was added to a stirred solution of Ph2L1SnCl (0.06 g, 0.1 mmol)
in CH2Cl2 (10 mL). The suspension was stirred for 5 days at
C
29H35F3O5SSn (MW 671.35): C, 51.08, H 5.25. Found: C,
50.99, H 5.15. MS: m/z 321, 46%, [2 × CF3SO3 + Na]-, m/z
149, 100%, [CF3SO3]-, m/z 523, 100%, [M - CF3SO3]+. 1H NMR
(CDCl3, 360 MHz): δ (ppm) 1.05 (s, 18H, CH3), 4.87 (s, 4H,
CH2, nJ (119Sn,1H) ) 8.7 Hz), 7.30-7.75 (complex pattern, 13H,
SnPh2, SnC6H3). 13C NMR (CDCl3, 90 MHz): δ (ppm) 27.8
(CH3), 65.0 (CH2, nJ (119Sn,13C) ) 19.4 Hz), 84.5 (OCMe3), 122.5
(CF3, nJ (19F,13C) ) 320.2 Hz), SnC6H3, 119.7 (C(1), 1J (119Sn,13C)
) 760.1 Hz),), 143.7, 124.3, 132.0, SnPh2: 139.9 (C(1′),
(22) These values of tin chemical shift are typical for pentacoordi-
nated organotin(IV) C3Sn+ cations with trans-trigonal bipyramidal
geometry (carbon atoms form an equatorial plane and two donor atoms
are in axial position) found in triorganotin compounds containing
N,C,N-chelating ligands.
(23) Sokrates, G. Infrared Characteristic Group Frequencies; 1980.

Quest for Organotin(IV) Cations
Organometallics, Vol. 23, No. 22, 2004 5307
1J (119Sn,13C) ) 742.6 Hz), 136.1, 130.2, 132.1. IR (suspension
in Nujol): νas(SO3) 1267 cm-1; (solution in CHCl3) νas(SO3) )
detector by monochromatized Mo KR radiation (λ ) 0.71073
Å) at 150(2) K. The crystallographic details are summarized
in Table 1, and empirical absorption corrections24 were applied
(multiscan from symmetry-related measurements). The struc-
tures were solved by the direct method (SIR9725) and refined
1262 cm-1
Syn t h esis
.
of
[2,6-Bis(m et h oxym et h yl)p h en yl]d i-
p h en yltin Hexa flu or op h osp h a te [7]. Ph3CPF6 (0.03 g, 0.1
mmol) was added to a stirred solution of Ph3L1Sn (0.06 g, 0.1
mmol) in toluene (20 mL). The suspension was stirred for 2
days at 25 °C, and the solid was filtered off and washed with
two portions of chloroform (20 mL) to provide 7 as a brownish
solid. Yield: 0.18 g (80%); mp 340 °C (dec). Anal. Calcd for
by
a
full-matrix least-squares procedure based on F2
(SHELXL9726). Hydrogen atoms were fixed into idealized
positions (riding model) and assigned temperature factors Hiso
(H) ) 1.2Ueq(pivot atom); for the methyl moiety a multiple of
1.5 was chosen. The final difference maps displayed no peaks
of chemical significance. Crystallographic data for structural
analysis have been deposited with the Cambridge Crystal-
lographic Data Centre, CCDC no. 237988, 237989, 237990, and
237991 for 1, 3, 5, and 6, respectively. Copies of this informa-
tion may be obtained free of charge from The Director, CCDC,
12 Union Road, Cambridge CB2 1EY, UK (fax: +44-1223-
336033; e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
-
C
22H23F6O2PSn (MW 583.08): C, 45.32; H, 3.98. Found: C,
45.45; H, 4.03. MS: m/z 145, 100%, [PF6]-, m/z 439, 100%, [M
- PF6]+. IR (suspension in Nujol): ν(PF6) 878, 343 cm-1
.
Syn t h esis of [2,6-Bis(ter t-b u t oxym et h yl)p h en yl]d i-
p h en yltin Hexa flu or op h osp h a te [8]. Ph3CPF6 (0.09 g, 0.2
mmol) was added to a stirred solution of Ph3L2Sn (0.1 g, 0.2
mmol) in toluene (10 mL). The suspension was stirred for 4
days at 55 °C. The solid was filtered off and washed with two
portions of chloroform (20 mL) to provide 8 as a brownish solid.
Yield: 0.098 g (70%); mp 355°C (dec). Anal. Calcd for
Ack n ow led gm en t. The authors would like to thank
J irˇ´ı Brus for CP/MAS NMR, Dr. Michal Holcˇapek and
Lenka Kola´rova´ for ESI-MS, and the Grant Agency of
the Czech Republic (grants no. 203/03/P128, 203/03/1072
and 203/04/0223) for financial support.
C
28H35F6O2PSn (MW 667.24): C, 50.40; H, 5.29. Found: C,
50.25; H 5.33. MS: m/z 145, 100%, [PF6]-, m/z 523, 100%, [M
- PF6]+. IR (suspension in Nujol): ν(PF6) 878, 342 cm-1
Syn t h esis of [2,6-Bis(m et h oxym et h yl)p h en yl]d i-
.
p h en yltin Tr iiod om er cu r a te [9]. HgI2 (0.08 g, 0.2 mmol)
was added to a stirred solution of 1 (0.1 g, 0.2 mmol) in CH2-
Cl2 (10 mL). The suspension was stirred for 30 min at 25 °C,
and the solvent was evaporated in vacuo to provide 9 as an
orange solid. Yield: 0.105 g (75%); mp 142°C (dec). Anal. Calcd
for C22H23HgIO2Sn (MW 1019.42): C, 25.92, H, 2.27. Found:
C, 25.75, H, 2.19. MS: m/z 127, 17%, [I]-, m/z 582, 100%,
[HgI3]-, m/z 439, 100%, [M - HgI3]+. 1H NMR (CDCl3, 360
MHz): δ (ppm) 3.56 (s, 6H, CH3), 5.02 (s, 4H, CH2), 7.30-
7.70 (complex pattern, 13H, SnPh2, SnC6H3).
Cr ysta llogr a p h y Stu d ies. Colorless crystals were obtained
from layering of n-hexane onto a dichloromethane solution of
the compound. Crystals of compounds of 1, 3, 5, and 6 were
mounted on a glass fiber with epoxy cement and measured on
a KappaCCD four-circle diffractometer with a CCD area
Su p p or tin g In for m a tion Ava ila ble: Tables of all crystal
data and structure refinement, atomic coordinates, anisotropic
displacement parameters, and geometric data for compounds
1, 3, 5, and 6. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM049636F
(24) (a) SORTAV: Blessing, R. H. J . Appl. Crystallogr. 1997, 30,
421 (b) PLATON: Spek, A. L. J . Appl. Crystallogr. 2003, 36, 7.
(25) Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.;
Burla, M. C.; Polidori, G.; Camalli, M. J . Appl. Crystallogr. 1994, 27,
435.
(26) Sheldrick, G. M. SHELXL97; University of Go¨ttingen: Ger-
many, 1997.