Chalcogenide/chalcogenolate structural isomers of organo group 13 element derivatives: reactions of the dimetallenes Ar#MMAr# (Ar# = CH - 2,6-(CH - 2,6-Pr; M = Ga or In) with NO or S to give (Ar#ME) (E = O or S) and the synthesis and characterization of [

Article abstract of DOI:10.1021/om900031v

arylgallium/indium chalcogenides 7-10 of formula [Ar'ME]2 (Ar' = C6H3-2,6-(C6H3-2,6- Pri2)2;M = Ga or In, E = O or S) were synthesized by the treatment of Ar'MMAr' with N2O or elemental sulfur and characterized by NMR spectroscopy and X-ray crystallograph

Full text of DOI:10.1021/om900031v

2512
Organometallics 2009, 28, 2512–2519
Chalcogenide/Chalcogenolate Structural Isomers of Organo Group
13 Element Derivatives: Reactions of the Dimetallenes Ar′MMAr′
(Ar′ ) C6H3-2,6-(C6H3-2,6-Pri2)2; M ) Ga or In) with N2O or S8 To
Give (Ar′MIIIE)2 (E ) O or S) and the Synthesis and
Characterization of [Ar′EMI]2 (M ) In or Tl; E ) O, S)
Zhongliang Zhu, Robert J. Wright, Zachary D. Brown, Alexander R. Fox,
Andrew D. Phillips, Anne F. Richards, Marilyn M. Olmstead, and Philip P. Power*
Department of Chemistry, UniVersity of California DaVis, One Shields AVenue, DaVis, California 95616
ReceiVed January 14, 2009
Dimeric arylgallium/indium chalcogenides 7-10 of formula [Ar′ME]2 (Ar′ ) C6H3-2,6-(C6H3-2,6-
Pri2)2; M ) Ga or In, E ) O or S) were synthesized by the treatment of Ar′MMAr′ with N2O or elemental
sulfur and characterized by NMR spectroscopy and X-ray crystallography. Their structures feature three-
coordinate, +3 oxidation state metal centers with planar M2E2 cores. The cores were almost perfectly
square for E ) O, but for E ) S, they were distorted parallelograms in 7-10. The M–E bond lengths
were shorter than those in the higher aggregated species [RME]n (n g 4) but comparable to those in M3+
aryloxides or thiolates featuring three-coordinate metals. Short M · · · M separations [2.553(1) Å in 7,
2.8882(4) Å in 8, 2.8276 Å (avg.) in 9, and 3.1577(8) Å in 10] are observed. Low oxidation heavier
group 13/group 16 chalcogenolate isomers 16-19 of formula [Ar′EM]2 (M ) In or Tl, E ) O or S) were
also synthesized and characterized. In the +1 compounds [Ar′EIn]2 (O, 16; S, 19) together, with the In
+3 species [Ar′InE]2 (O, 8; S, 10), represent the first structurally characterized isomeric pairs of organo
group 13 metal/chalcogen derivatives. The E-M bonds in 16-19 were 2.3329 (avg.), 2.560 (avg.), 2.8189
(avg.), and 2.897 Å (avg.), respectively, which are 0.3-0.4 Å longer than the corresponding In-chalcogen
distances in 8 and 10 as a result of the lower oxidation state, the large In+ ionic size, and the reduced
ionic contribution to the bond strength in 16 and 19. The compounds 16-19 also displayed M-arene
interactions to the flanking aryl rings of the Ar′ ligands. The Tl-arene contacts in the crystal structure
of 17 are preserved in solution, as evidenced by 13C-Tl coupling. Attempts to thermally interconvert the
isomeric pairs 8, 10 and 16, 18 led to decomposition of the complexes.
(R ) alkyl, silyl, and related group, M ) Al, Ga, or
In)3b,c,e,4a,b,d,5-7 in which the chalcogens µ3-bridge the metals
are the most common structures, the stability of which is
Introduction
Organometallic compounds of heavier group 13 metal chal-
cogenides of formula [RME]n (R ) organic or related susb-
stituent; M ) Al, Ga or In; E ) O or S) have attracted
considerable interest because of their potential application as
semiconductor precursors for MOCVD.1 A variety of these
organometal oxides and sulfides have been synthesized, and a
number of different structural types have been reported.2-7,9-13
They are mainly oligomers, whose association numbers gener-
ally range from 4 to 8. Tetrameric cubanes of formula [RME]4
(4) (a) Capparelli, M. V.; Hodge, P.; Piggott, B. Chem. Commun. 1997,
937. (b) Storre, J.; Klemp, A.; Roesky, H. W.; Fleischer, R.; Stalke, D.
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H.-W.; No¨th, H.; Ponikwar, W.; Schwenk, H. J. Organomet. Chem. 1999,
574, 246. (d) Wiberg, N.; Blank, T.; Amelunxen, K.; No¨th, H.; Schno¨ckel,
H.; Baum, E.; Purath, A.; Fenske, D. Eur. J. Inorg. Chem. 2002, 341.
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Contreras, L.; Burek, C. J. Angew. Chem., Int. Ed. Engl. 1991, 30, 1143.
(b) Power, M. B.; Barron, A. R. J. Chem. Soc., Chem. Commun. 1991,
1315. (c) Power, M. B.; Ziller, J. W.; Barron, A. R. Organometallics 1992,
11, 2783. (d) Shang, G.; Hampden-Smith, M. J.; Duesler, E. N. Inorg. Chem.
1996, 35, 2611. (e) Gillan, E. G.; Bott, S. G.; Barron, A. R. Chem. Mater.
1997, 9, 796. (f) App, U.; Merzweiler, K. Z. Anorg. Allg. Chem. 1997,
623, 478. (g) Linti, G.; Bu¨hler, M.; Urban, H. Z. Anorg. Allg. Chem. 1998,
624, 517. (h) Schnitter, C.; Klemp, A.; Roesky, H. W.; Schmidt, H.-G.;
Ro¨pken, C.; Herbst-Irmer, R.; Noltemeyer, M. Eur. J. Inorg. Chem. 1998,
2033. (i) Barbarich, T. J.; Bott, S. G.; Barron, A. R. J. Chem. Soc., Dalton
Trans. 2000, 1679.
* To whom correspondence should be addressed. E-mail:
pppower@ucdavis.edu.
(1) (a) Barron, A. R. AdV. Mater. Opt. Electron. 1995, 5, 245. (b)
Bochmann, M. Chem. Vapor Depos. 1996, 2, 85. (c) Shang, G. H.; Kunze,
K.; Hampden-Smith, M. J.; Duesler, E. N. Chem. Vapor Depos. 1996, 2,
242. (d) Gleizes, A. N. Chem. Vapor Depos. 2000, 6, 155. (e) Schulz, S. In
AdVances in Organometallic Chemistry; Academic Press Inc.: San Diego,
CA, 2003; Vol. 49, p 225. (f) Gubin, S. P.; Kataeva, N. A.; Khomutov,
G. B. Russ. Chem. Bull. 2005, 54, 827. (g) Takebe, H.; Kitagawa, R.; Hewak,
D. W. J. Ceram. Soc. Jpn. 2005, 113, 37.
(6) Uhl, W.; Pohlmann, M. Chem. Commun. 1998, 451.
(2) Roesky, H. W.; Haiduc, I.; Hosmane, N. S. Chem. ReV. 2003, 103,
(7) (a) Merzweiler, K.; Rudolf, F.; Brands, L. Z. Naturforsch., B 1992,
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2579.
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Chem. Soc. 1993, 115, 4971. (b) Harlan, C. J.; Mason, M. R.; Barron, A. R.
Organometallics 1994, 13, 2957. (c) Harlan, C. J.; Gillan, E. G.; Bott, S. G.;
Barron, A. R. Organometallics 1996, 15, 5479. (d) Klimek, K. S.; Prust,
J.; Roesky, H. W.; Noltemeyer, M.; Schmidt, H.-G. Organometallics 2001,
20, 2047. (e) Zhu, H.; Chai, J.; Jancik, V.; Roesky, H. W.; Merrill, W. A.;
Power, P. P. J. Am. Chem. Soc. 2005, 127, 10170–10171.
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10.1021/om900031v CCC: $40.75
2009 American Chemical Society
Publication on Web 03/31/2009

Chalcogenide/Chalcogenolate Structural Isomers
Organometallics, Vol. 28, No. 8, 2009 2513
supported by theoretical calculations.8 Lower aggregation, in
which some multiple bonded character is a possibility, is rare,
and usually requires the use of sterically encumbering ligands.
The dimeric oxo species [RGaO]2 (R ) HC{(CMe)(2,6-
Pri2C6H3N)}2) (1)9a and K2[RGaO]2 (R ) {N(2,6-Pri2C6-
But)2) (14)19 and the amide:GaN(SiMe3)Ar′′ (Ar′′ ) C6H3-2,6-
(C6H2-2,4,6-Me3)2) (15),19 which contain short M-N bonds with
multiple character. The fact that the bulky terphenyl ligand can
effectively stabilize two isomeric forms of the gallium com-
pounds 14 and 15 prompted speculation as to whether the
terphenyl ligand Ar′ could also stabilize low oxidation heavier
group 13/group 16 chalcogenolate isomers of formula [Ar′EM]2
(M ) Ga, In, or Tl; E ) O or S). We now report the synthesis
of a range of low aggregated heavier group 13 metal organoch-
alcogenides [Ar′ME]2 (M/E ) Ga/O, 7; In/O, 8; Ga/S, 9; or
In/S, 10) by the use of the sterically hindered terphenyl ligand
Ar′, all of which feature three-coordinate metal centers and two-
coordinate chalcogenides. We also describe the synthesis and
characterization of the isomeric M(I) chalcogenolates [Ar′EM]2
(E/M ) O/In, 16; O/Tl, 17; S/In, 18; or S/Tl, 19), which feature
two-coordinate metals and three-coordinate chalcogen centers.
H3N)C(H)}2) (2),10 have been reported but both of these feature
t
four-coordinate metals. A terminal sulfide complex TpBu 2GaS
(Tp ) pyrazolylhydroborate) (3)11 featuring a very short Ga-S
bond of 2.093(2) Å together with a structurally characterized
dimeric gallium sulfide [RGaS]2 (R ) HC{(CMe)(2,6-
Pri2C6H3N)}2, 4),9a which feature four-coordinate metals, are
the only organogallium sulfides with association number less
than 4. The related aluminum sulfide dimer (Mes*AlS)2 (Mes*
) C6H2-2,4,6-But3) is also known.9b In contrast, low aggregated
indium chalcogenides of formula [RInE]n (n < 4) are unknown.
t
Attempts to use TpBu In to synthesize a gallium sulfide analogue
2
of indium resulted in the sulfur-rich five-membered ring species
t
t
12
13
2
2
TpBu In(η -S4) (5). A similar structure of TmBu In(η -S4) (6)
2
2
Experimental Section
t
was obtained by reacting TmBu In (Tm ) 2-mercaptoimida-
zolylhydroborate) with elemental sulfur. We draw attention to
the fact that it is possible to generate and study monomeric group
13 element two-coordinate species such as OAlX (X ) F or
Cl) in argon matrices at low temperature. However, none has
been isolated at room temperature.14
2
General Procedures. All manipulations were carried out by
using modified Schlenk techniques under an atmosphere of N2 or
in a vacuum atmospheres HE-43 drybox. Solvents were dried
according to the method of Grubbs and degassed prior to use.20
Tl(C5H5) (Aldrich) and InCl (Strem) were purchased and used as
received. The dimetallenes Ar′MMAr′ (M ) Ga,21 In,22 and Tl23),
the chalcogenols Ar′EH (E ) O24 and S25), and their lithium salts
Ar′ELi (E ) O24 and S25) were synthesized by literature methods.
N2O (99.99% purity) was purchased from Airgas Corporation and
The above complexes feature metals in the oxidation state
+3. However, a different isomeric form, in which the metal
has the oxidation state +1, is also possible. These are the
monovalent metal species of formula REM, which are metal(I)
alkoxides/aryloxides or metal(I) thiolates. Theoretical calcula-
tions on the model compounds M-O-H (I) and H-MdO (II)
predicted that the M(I) hydroxide isomer was more stable than
the metal(III) oxide by ca. 45 kcal mol-1 for Ga15 and ca. 59
kcal mol-1 for In.16 Although well-defined Tl(I) species are well-
known,17 low oxidation state chalcogenolates of the other metals
in the group are rare. No stable example of gallium(I) species
of fomula [REGa]n has been reported, and the only stable
structurally characterized In(I) chalcogenolate molecular species
is the indium(I) phenoxide [2,4,6-(CF3)3-C6H2OIn]2 (11).18a In
addition, there are two related indium(I) complexes, [CF3SO3In]2
(12)18b and In(µ-OBut)3Sn (13),18c which have also been struc-
turally characterized. Several In(I) thiolates of formula InSR
(R ) Et, Bun, C6H11, Ph, C6H4-2-Me, 2-naphthyl or C6F5) have
been synthesized but their structures remain unknown.18d Recent
work in our group on group 13 metal 3+/1+ species featuring
isomeric imido/amido derivatives has yielded quasi-isomeric
gallium imide Ar′GaNAr# (Ar# ) C6H3-2,6-(C6H2-2,6-Me2-4-
1
used without further purification. H and 13C NMR spectra were
recorded on Varian 300 spectrometers and referenced to known
standards. Melting points were recorded using a Meltemp apparatus
and were not corrected. Elemental analyses were not carried out
on the complexes which crystallized with solvent.
[Ar′GaO]2 (7). Ar′GaGaAr′ (0.72 g, 0.77 mmol) was dissolved
in 50 mL of toluene to afford a deep green solution. This was treated
with N2O, and the color was quickly discharged to afford a colorless
solution within ca. 10 s. The toluene was then removed under
reduced pressure to yield a colorless residue, which was dissolved
in 75 mL of hexane. The hexane was concentrated to ca. 50 mL,
and overnight storage at ca. -18 °C yielded colorless X-ray quality
crystals of 7: yield 0.52 g (70%); mp >275 °C; 1H NMR (300 MHz,
C6D6, 25 °C) δ 1.06 (br, 24H, o-CH(CH3)2), 1.20 (br, 24H,
o-CH(CH3)2), 2.70 (sept, 8H, CH(CH3)2), 7.11-7.25 (m, 18H,
ArH); 13C {1H}NMR (75.5 MHz, C6D6, 25 °C) δ 23.5 (CH(CH3)2),
25.7 (CH(CH3)2), 31.2 (CH(CH3)2), 123.7, 126.9, 129.8, 140.2,
145.6, 147.3 (ArC), one ArC resonance is likely obscured by the
C6H6 signal, and i-C6H3 signal was not observed. Anal. Calcd for
C60H74Ga2O2: C, 74.55; H, 7.72. Found: C, 74.01; H, 7.89.
[Ar′InO]2 (8). Compound 8 was synthesized in an analogous
manner to 7. However, the reaction was slower, and the discharge
(12) Kuchta, M. C.; Parkin, G. Main Group Chem. 1996, 1, 291.
(13) Yurkerwich, K.; Buccella, D.; Melnick, J. G.; Parkin, G. Chem.
Commun. 2008, 3305.
(18) (a) Scholz, M.; Noltemeyer, M.; Roesky, H. W. Angew. Chem.,
lnt. Ed. Engl. 1989, 28, 1383. (b) MacDonald, C. L. B.; Corrente, A. M.;
Andrews, C. G.; Taylor, A.; Ellis, B. D. Chem. Commun. 2004, 250. (c)
Veith, M.; Kunze, K. Angew. Chem., lnt. Ed. Engl. 1991, 30, 95. (d) Green,
J. M.; Kumar, R.; Seudeal, N.; Tuck, D. G. Inorg. Chem. 1989, 28, 123.
(19) Wright, R. J.; Brynda, M.; Fettinger, J. C.; Betzer, A. R.; Power,
P. P. J. Am. Chem. Soc. 2006, 128, 12498.
(14) Schno¨ckel, H. J. Mol. Struct. 1978, 50, 267.
(15) (a) Richards, C. A., Jr.; Yamaguchi, Y.; Kim, S.-J.; Schaefer, H. F.,
III. J. Chem. Phys. 1996, 104, 8516. (b) Nowek, A.; Leszczynski, J. J.
Phys. Chem. 1994, 98, 13210.
(16) Arulmozhiraja, S.; Fujii, T.; Tokiwa, H. J. Phys. Chem. A 2006,
110, 3814.
(17) (a) Emsley, J. The Elements; Clarendon: Oxford, 1995. (b) Petrie,
M. A.; Olmstead, M. M.; Power, P. P. J. Am. Chem. Soc. 1991, 113, 8704.
(c) Cleaver, W. M.; Barron, A. R. Organometallics 1993, 12, 1001. (d)
Linti, G.; Frey, R.; Polborn, K. Chem. Ber. 1994, 127, 1387. (e) Niemeyer,
M. Organometallics 1998, 17, 4649. (f) Harrowfield, J. M.; Sharma, R. P.;
Skelton, B. W.; White, A. H. Aust. J. Chem. 1998, 735. (g) Uhl, W.;
Pohlmann, M. Chem. Commun. 1998, 451. (h) Neculai, D.; Roesky, H. W.;
Neculai, A. M.; Magull, J.; Walfort, B.; Stalke, D. Angew. Chem., Int. Ed.
2002, 41, 4294. (i) Mahjoub, A. R.; Morsali, A.; Bagherzadeh, H.
Polyhedron 2002, 21, 2555. (j) Vidovic, D.; Moore, J. A.; Jones, J. N.;
Cowley, A. H. J. Am. Chem. Soc. 2005, 127, 4566. (k) Robertson, D.;
Cannon, J. F.; Gerasimchuk, N. Inorg. Chem. 2005, 44, 8326.
(20) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J. Organometallics 1996, 15, 1518.
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Chem. Soc. 2003, 125, 2667.
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2514 Organometallics, Vol. 28, No. 8, 2009
Zhu et al.
of the color was complete only after 2 min. Colorless X-ray quality
crystals of 8 were grown from hexane upon slow cooling of
saturated solutions at ca. -18 °C: yield 0.57 g (65%); mp >275
°C; 1H NMR (300 MHz, C6D6, 25 °C) δ 1.01 (d, 48H, o-CH(CH3)2,
m-C6H3,3JHH ) 7.2 Hz), 7.08 (br, 12H, m-Dipp, and p-Dipp); 13C
{1H}NMR (C6D6, 75.5 MHz, 25 °C) δ 25.1 (CH(CH3)2), 25.7
(CH(CH3)2), 31.1 (CH(CH3)2), 113.8 (p-C6H3), 125.1 (t, m-Dipp,
JC-Tl ) 52 Hz), 128.7, 129.8 (t, p-Dipp, JC-Tl ) 23 Hz), 130.9,
143.3 (t, i-Dipp, JC-Tl ) 70 Hz), 148.9 (t, o-Dipp, JC-Tl ) 37 Hz),
165.1 (i-C6H3). Anal. Calcd for C60H74O2Tl2: C, 58.3; H, 6.04.
Found: C, 58.01; H, 6.17.
3
3JHH ) 6.6 Hz), 2.96 (sept, 8H, CH(CH3)2, JHH ) 6.6 Hz),
7.16-7.37 (m, 18H, ArH); 13C {1H}NMR (75.5 MHz, C6D6, 25
°C) δ 26.2 (CH(CH3)2), 26.6 (CH(CH3)2), 30.8 (CH(CH3)2), 123.4,
127.9, 129.4, 140.7, 142.1, 147.0, 147.8, 197.6 (ArC).
[Ar′SIn]2 (18). Compound 18 was synthesized in an analogous
manner to 16 from Ar′SLi (0.40 g, 0.92 mmol) and InCl (0.14 g,
0.93 mmol). Pale green X-ray quality crystals were grown from a
saturated toluene solution upon slow cooling and overnight storage
at ca. -18 °C: yield 0.38 g (76%); mp, decomposed to a black
[Ar′GaS]2 (9). A suspension of crystalline sulfur (0.048 g, 1.50
mmol) in toluene (20 mL) was added dropwise over 20 min to a
mixture of Ar′GaGaAr′ (0.70 g, 0.75 mmol) and toluene (40 mL)
at -78 °C. Upon slowly warming to room temperature, the deep
green solution of Ar′GaGaAr′ faded to colorless, and the mixture
solution was stirred overnight. Toluene was then removed under
reduced pressure to afford a colorless residue, which was dissolved
in 70 mL of benzene. The benzene was concentrated to ca. 20 mL,
and storage at ca. 7 °C for 1 week yielded colorless X-ray quality
crystals of 9: yield 0.21 g (28%); mp 315 °C; 1H NMR (300 MHz,
1
solid upon heating; H NMR (300 MHz, C6D6, 25 °C) δ 1.08 (d,
24H, o-CH(CH3)2, 3JHH ) 6.6 Hz), 1.35 (d, 24H, o-CH(CH3)2, 3JHH
) 6.6 Hz), 2.89 (sept, 8H, CH(CH3)2, 3JHH ) 6.6 Hz), 6.89 (t, 2H,
3
3
p-C6H3, JHH ) 7.8 Hz), 6.94 (d, 4H, m-C6H3, JHH ) 7.2 Hz),
3
3
7.09 (t, 4H, p-Dipp, JHH ) 7.8 Hz), 7.21 (d, 8H, m-Dipp, JHH
)
7.8 Hz); 13C {1H}NMR (75.5 MHz, C6D6, 25 °C) δ 25.0
(CH(CH3)2), 31.0 (CH(CH3)2), 122.1, 124.7, 129.2, 140.9, 142.9,
144.8, 147.3, and 219.8 (ArC).
3
C6D6, 25 °C) δ 1.05 (d, 24H, o-CH(CH3)2, JHH ) 7.2 Hz), 1.28
3
(d, 24H, o-CH(CH3)2, JHH ) 7.2 Hz), 2.82 (sept, 8H, CH(CH3)2,
3JHH ) 6.6 Hz), 7.16 (d, 4H, m-C6H3, 3JHH ) 6.0 Hz), 7.18 (d, 8H,
m-Dipp, 3JHH ) 7.8 Hz), 7.20 (t, 2H, p-C6H3, 3JHH ) 6.6 Hz), 7.39
[Ar′STl]2 (19). Compound 19 was synthesized in an analogous
manner to 17. However, upon removal of the hexane solvent, the
colorless residue was extracted with hot (100 °C) toluene. Colorless
X-ray quality crystals of 19 were grown from saturated toluene
solutions upon slow cooling and overnight storage at ca. 0 °C: yield
3
(t, 4H, p-Dipp, JHH ) 7.8 Hz); 13C {1H}NMR (75.5 MHz, C6D6,
25 °C) δ 23.0 (CH(CH3)2), 26.1 (CH(CH3)2), 30.9 (CH(CH3)2),
123.6, 127.9, 129.2, 129.7, 139.9, 146.3, and 147.1 (ArC), i-C6H3
signal was not observed.
1
0.52 g (50%); mp >275 °C; H NMR (300 MHz, C7D8, 25 °C) δ
3
[Ar′InS]2 (10). Compound 10 was synthesized in an analogous
manner to 9 from Ar′InInAr′ (0.60 g, 0.58 mmol) and sulfur (0.037
g, 1.16 mmol). Colorless X-ray quality crystals of 10 were grown
from a mixture of hexane (20 mL) and toluene (2 mL) upon slow
cooling of a saturated solution at ca. -50 °C for 5 days: yield 0.15 g
(24%); mp >350 °C; 1H NMR (300 MHz, C6D6, 25 °C) δ 1.05 (d,
24H, o-CH(CH3)2, 3JHH ) 6.6 Hz), 1.32 (d, 24H, o-CH(CH3)2, 3JHH
1.08 (d, 24H, o-CH(CH3)2, JHH ) 6.9 Hz), 1.30 (d, 24H,
3
3
o-CH(CH3)2, JHH ) 6.9 Hz), 2.89 (sept, 8H, CH(CH3)2, JHH
)
6.9 Hz), 6.82-7.00 (m, 6H, p-C6H3, p-C6H3), 7.04 (d, 4H, m-C6H3,
3JHH ) 7.5 Hz), 7.18 (d, 8H, m-Dipp, 3JHH ) 7.5 Hz); 13C{1H}NMR
(75.5 MHz, C7D8, 25 °C) δ 24.6 (CH(CH3)2), 24.9 (CH(CH3)2),
30.9 (CH(CH3)2), 121.3, 137.5, 143.1, 147.6, three ArC resonances
are likely obscured by the C6H6 signal, and i-C6H3 signal was not
observed.
3
) 7.2 Hz), 2.87 (sept, 8H, CH(CH3)2, JHH ) 7.2 Hz), 7.22 (m,
3
6H, m-C6H3 and p-C6H3), 7.24 (d, 8H, m-Dipp, JHH ) 7.2 Hz),
X-ray Structure Determination. Crystals of 7-10 and 16-19
were removed from a Schlenk tube under a stream of nitrogen and
immediately covered with a thin layer of hydrocarbon oil. A suitable
crystal was selected, attached to a glass fiber, and quickly placed
in a low temperature stream.26 The data for 7-9, 17, and 19 were
recorded near 90 K on a Bruker SMART 1000 instrument (Mo
KR radiation (λ ) 0.71073 Å) and a CCD area detector), while
data for 16 were collected at 180 K, and data for 10 and 18 were
collected at 90 K on a Bruker APEX instrument (Mo KR radiation
and a CCD area detector). For compounds 7, 8, 10, and 16-19,
the SHELX version 6.1 program package was used for the structure
solutions and refinements. Absorption corrections were applied
using the SADABS program.27 The crystal structures were solved
by direct methods and refined by full-matrix least-squares proce-
dures. All non-hydrogen atoms were refined anisotropically.
Hydrogen atoms were included in the refinement at calculated
positions using a riding model included in the SHELXTL program.
Crystals of 9 were formed to be twinned, and the relative
contributions from the two twin components were determined by
using Cellnow program.28 Absorption corrections were applied
using the TWINABS program, and the major component was used
for structure determination.29,30 The BASF parameter refined to
0.436, indicating that a nearly equal percentage of the two domains
3
7.42 (t, 4H, p-Dipp, JHH ) 7.8 Hz); 13C {1H}NMR (75.5 MHz,
C6D6, 25 °C) δ 23.2 (CH(CH3)2), 26.0 (CH(CH3)2), 30.9
(CH(CH3)2), 124.0, 129.6, 141.9, 146.9, and 147.0 (ArC), two ArC
resonances are likely obscured by the C6H6 signal, and i-C6H3 signal
was not observed.
[Ar′OIn]2 (16). Ar′OLi (0.70 g, 1.73 mmol) was dissolved in
toluene (50 mL) and added dropwise over 30 min to a mixture of
InCl (0.26 g, 1.73 mmol) and toluene (20 mL) at -78 °C. The
solution was slowly warmed to room temperature and stirred
overnight. Toluene was then removed under reduced pressure, and
hexane (70 mL) was used to extract the colorless residue.
Concentration to ca. 20 mL and overnight storage at ca. -18 °C
afforded colorless X-ray quality crystals of 16: yield 0.45 g (52%);
mp, decomposed to a black solid upon heating; 1H NMR (300 MHz,
3
C6D6, 25 °C) δ 1.09 (d, 24H, o-CH(CH3)2, JHH ) 7.8 Hz), 1.20
3
(d, 24H, o-CH(CH3)2, JHH ) 7.2 Hz), 2.99 (sept, 8H, CH(CH3)2,
3JHH ) 6.6 Hz), 6.77 (t, 2H, p-C6H3, 3JHH ) 7.2 Hz), 7.04 (d, 4H,
3
3
m-C6H3, JHH ) 7.2 Hz), 7.11 (d, 8H, m-Dipp, JHH ) 7.8 Hz),
7.18 (t, 4H, p-Dipp, JHH ) 7.2 Hz); 13C {1H}NMR (75.5 MHz,
3
C6D6, 25 °C) δ 24.5 (CH(CH3)2), 25.2 (CH(CH3)2), 30.8
(CH(CH3)2), 115.7, 124.6, 128.7, 129.2, 131.0, 141.1, 147.9, and
219.8 (ArC). Anal. Calcd for C60H74In2O2: C, 68.18; H, 7.06. Found:
C, 67.70; H, 7.11.
[Ar′OTl]2 (17). Ar′OH (0.55 g, 1.33 mmol) was dissolved in
hexane (40 mL) and added dropwise over 20 min to a mixture of
Tl(C5H5) (0.38 g, 1.40 mmol) and hexane (40 mL). The mixture
was stirred overnight, filtered through a layer of Celite, and
concentrated to ca. 30 mL. Overnight storage at ca. -30 °C for 3
days afforded colorless X-ray quality crystals of 17: yield 0.80 g
(26) Hope, H. Prog. Inorg. Chem. 1995, 41, 1.
(27) SADABS. An empirical absorption correction program, part of the
SAINT-Plus NT version 5.0 package; Bruker AXS: Madison, WI, 1998.
(28) Sheldrick, G. M. (private communication)CELLNOW, Twin matrix
determination program; Universita¨t Go¨ttingen: Go¨ttingen, Germany, 2003.
(29) Blessing, R. H. An Empirical Correction for Absorption Anisotropy.
Acta Crystallogr. 1995, A51, 33–38.
1
(65%); mp >275 °C; H NMR (300 MHz, C6D6, 25 °C) δ 1.13 (t,
(30) Sheldrick, G. M. (private communication)TWINABS ‘An Empirical
Correction for Absorption Anisotropy applied to Twinned crystals’ v1.05;
Universita¨t Go¨ttingen: Go¨ttingen, Germany, 2003.
48H, o-CH(CH3)2, 3JHH ) 6.6 Hz), 3.09 (sept, 8H, CH(CH3)2, 3JHH
3
) 6.9 Hz), 6.71 (t, 2H, p-C6H3, JHH ) 7.2 Hz), 7.02 (d, 4H,

Chalcogenide/Chalcogenolate Structural Isomers
Organometallics, Vol. 28, No. 8, 2009 2515
Table 1. Selected Crystallographic Data for 7, 8 · 0.5C6H14, 9 · 4C6H6, 10 · 2C7H8, 16, 17, 18 · 3.5C7H8, and 19 · 2.4C7H8
cmpd
7
8 · 0.5C6H14
C66H82In2O2
1136.96
block
9 · 4C6H6
10 · 2C7H8
C74H90In2S2
1273.24
block
formula
C60H74Ga2O2
966.63
block
C84H98Ga2S2
1311.18
block
fw
habit
cryst syst
space group
a, Å
b, Å
c, Å
orthorhombic
Pccn
20.116(4)
15.881(3)
16.472(3)
90
monoclinic
C2/m
15.8883(13)
20.6514(15)
11.8851(9)
90
129.086(3)
90
3026.9(4)
4
triclinic
Pnma
monoclinic
P21/n
11.8879(17)
21.738(3)
12.6705(18)
90
99.673(2)
90
3227.7(8)
2
12.998(2)
23.678(4)
23.675(4)
92.600(3)
96.329(3)
96.269(3)
7187(2)
4
R, deg
ꢀ, deg
90
90
γ, deg
V, Å3
5262.2(18)
4
Z
cryst dim, mm
dcalcd, g · cm-3
µ, mm-1
no. of reflns
no. of obsd reflns
R1 obsd reflns
wR2, all
0.18 × 0.17 × 0.08
0.24 × 0.21 × 0.19
0.49 × 0.48 × 0.44
0.21 × 0.11 × 0.09
1.220
1.247
1.212
1.143
1.064
5162
3508
0.0574
0.1624
0.802
13889
4199
0.0299
0.851
35493
29557
0.0437
0.810
7499
4806
0.0479
0.0762
0.1240
0.1244
cmpd
formula
fw
16
17
18 · 3.5C7H8
C84.5H102S2In2
1411.45
plate
19 · 2.4C7H8
C77H82S2Tl2
1486.33
block
C60H74In2O2
1056.83
needle
C60H70O2Tl2
1235.94
block
habit
cryst syst
space group
a, Å
b, Å
c, Å
monoclinic
P21/c
9.125(3)
22.769(7)
24.577(7)
90
96.519(4)
90
5073(3)
4
orthorhombic
Pccn
13.0543(13)
19.3442(19)
20.716(2)
90
90
90
5231.4(9)
4
monoclinic
P21/n
16.5924(16)
16.5192(16)
27.739(3)
90
105.0310(10)
90
7343.0(12)
4
monoclinic
P21/n
16.5924(17)
16.5655(18)
28.365(3)
90
109.397(6)
90
7353.9(13)
4
R, deg
ꢀ, deg
γ, deg
V, Å3
Z
cryst dim, mm
dcalcd, g · cm-3
µ, mm-1
no. of reflns
no. of obsd reflns
R1 obsd reflns
wR2, all
0.40 × 0.17 × 0.14
0.24 × 0.21 × 0.19
0.56 × 0.52 × 0.30
0.34 × 0.21 × 0.18
1.381
1.564
1.277
1.342
0.951
11628
9324
0.0292
0.0693
6.193
6952
5342
0.0398
0.0974
0.728
13264
10814
0.0643
4.471
11471
9878
0.0794
0.1406
0.1949
Scheme 1. Synthetic Routes to Compounds 7-10
was present. Some details of the data collection and refinement
are given in Table 1.
Results and Discussion
Synthesis of [Ar′ME]2 (M/E ) Ga/O, 7; In/O, 8; Ga/S,
9; or In/S, 10) and (Ar′EM)2 (E/M ) O/In, 16; O/Tl, 17;
S/In, 18; or S/Tl, 19). Heavier organo group 13 metal
chalcogenides [RME]n have been prepared preferentially by (1)
protolysis of R3M or RMMe2 with H2E followed by thermo-
lysis,3a-d,4b,5c,h (2) ligand exchange between organo metal
halides and various chalcogen-transfer reagents,5e,f,7a (3) reaction
of R3M or R2MH with elemental chalcogens,5a-d,11 or (4)
oxidation of RM.3e,4c,d,6,7b,9-13 Recently, our group reported a
facile synthetic route to the ꢀ-diketiminates [RGaE]2 (R )
HC{(CMe)(2,6-Pri2C6H3N)}2, E ) O or S) via oxidation of the
monomeric:GaR (R ) HC{(CMe)(2,6-Pri2C6H3N)}2), which
resulted in a low aggregated organogallium oxide or sulfide.
We were thus encouraged to apply a similar strategy for the
synthesis of aryl metal oxides and sulfides from the low
oxidation dimetallenes Ar′GaGaAr′ and Ar′InInAr′. The dimeric
organo gallium and indium oxide, 7 and 8, were synthesized
by the oxidation of Ar′GaGaAr′ and Ar′InInAr′ with excess N2O
in toluene (Scheme 1). Colorless crystals of 7 and 8 were
obtained upon storage in hexane at ca. -18 °C. Treatment of
Ar′TlTlAr′ with N2O, O2, trimethylamine-N-oxide, or pyridine
N-oxide did not result in characterizable Tl(III) products.
1
Analysis of the reaction mixtures by H NMR spectroscopy
afforded resonances assignable only to starting materials and
some decomposition products (Tl and Ar′H). It is also note-
worthy that the isomeric [Ar′OTl]2 was not formed in these
experiments by insertion of O into the Tl-C bond, whereas
the related Cu(I) aryl, CuAr# (Ar# ) C6H2-2,6-Mesityl2), was
observed to react with O2 and, upon acidic work up, afforded
Ar#OH in modest yield.31 The dimeric organogallium and
indium sulfides, 9 and 10, were synthesized by the addition of
stoichiometric amounts of sulfur to toluene solutions of
Ar′GaGaAr′ and Ar′InInAr′ at -78 °C followed by overnight
stirring at room temperature (Scheme 1). Upon storage of
saturated benzene solution of 9 and toluene/hexane (1/20)
mixture solution of 10, colorless crystals of both 9 and 10 were
(31) Niemeyer, M. Organometallics 1998, 17, 4649.

2516 Organometallics, Vol. 28, No. 8, 2009
Zhu et al.
Scheme 2. Synthetic Routes to Compounds 16-19
obtained. A similar reaction between Ar′TlTlAr′ and S8 did not
occur, and unreacted starting materials were recovered.
The dimeric indium phenoxide 16 and thiolate 18 were
synthesized via transmetalation with Ar′OLi or Ar′SLi and InCl
in toluene, respectively (Scheme 2). Upon storage of saturated
hexane solution of 16 or a toluene solution of 18 at ca. -18
°C, colorless crystals of 16 or pale green crystals of 18 were
obtained. The dimeric thallium analogues 17 and 19 were
synthesized by the reaction of Ar′OH and Ar′SH with Tl(C5H5)
in THF (Scheme 2). They were obtained in ca. 65% yield, as
X-ray quality crystals, upon storage of saturated hexane solution
of 17 and toluene solution of 19 at ca. -18 °C. A similar
transmetalation reaction between Ar′OLi or Ar′SLi and “GaI”32
in toluene resulted only in decomposition to Ar′OH or Ar′SH
and gallium metal. Attempts to reduce Ar′OGaCl2 or Ar′SGaCl2
with Na as well as the reaction between Ar′OH or Ar′SH and
the dimetallene Ar′GaGaAr′ were ineffective for the preparation
of the target [Ar′OGa]2 or [Ar′SGa]2 compounds. The oxo and
sulfide complexes 7-10 are characterized by high thermal
stabilities and do not melt below 300 °C. They show signs of
degradation after prolonged periods at this temperature. Attempts
to thermally convert 8 and 10 to the aryloxide 16 or thiolate 18
were unsuccessful.
Figure 2. Thermal ellipsoid (50%) drawing of 10. Hydrogen atoms
are not shown. Dihedral angles between In2S2 plane and C(1)-C(6)
ring ) 85.93°.
distances of 1.828(3) Å in 7 and 2.026(1) Å in 8. Similar square
planar Ga2O2 arrays were observed in ꢀ-diketiminato gallium
oxide [RGaO]2 (R ) HC{(CMe)(2,6-Pri2C6H3N)}2, 1)9 and a
related dianion K2[RGaO]2 (R ) {N(2,6-Pri2C6H3N)C(H)}2)
(2).10 Ga-O distances are 1.8536(9) and 1.8485(9) Å in 1, and
two different Ga-O distances of 1.814(3) and 1.905(3) Å,
respectively, were found in 2. Thus the Ga-O distances in 1
and 2 are ca. 0.2 Å longer than those in 7, most probably as a
result of the higher coordination number of the gallium. The
Ga-O bond length is quite similar to the 1.821(3), 1.822(3),
and 1.831(4) Å in the three-coordinate species But2GaO(C6H3-
2,6-But2-4-Me) (23),33a (2,2,6,6,- tetramethylpiperidino)2GaOPh
(24),33b and But2GaOCPh3 (25)33c in 7. The structurally char-
acterized, higher aggregated organogallium oxides all involve
four-coordinate metals and include one nonamer (MesGaO)9
(Mes ) 2,4,6-Me3C6H2, 20)4b and two cubane tetramers
[But3SiGaO]4 (21)4c and [GaCl(pz)3GaO]4 (22, pz ) tris-
(pyrazolyl)borate).4a In 20, two six-membered (MesGaO)3 rings
are connected by three µ2-MesGaO units, thus generating two
sets of Ga-O bonds [1.910 Å (avg.) in (MesGaO)3 rings and
1.967 Å (avg.) in µ2-MesGaO units]. Compounds 21 and 22
both feature oxygens that symmetrically µ3-bridge the gallium
atoms. The Ga-O distances are 1.91 (avg.) and 2.003(1) Å,
respectively. Because of the higher metal coordination, 20-22
have considerably longer Ga-O bonds (all exceed 1.9 Å) than
those in 1, 2, and 7. The In-O bonds in 8 have similar
characteristics to its gallium analogue. The In-O bonds are
shorter than the average In-O bonds of 2.14 Å in the tetrameric
[RInO]4 (R ) (Me3Si)3C) (26)6 and are similar to 2.091(4) Å
in three-coordinate indium species Cp*Fe(CO)2In(OC6H4-4-
But)Mes* (Mes* ) C6H3-2,4,6-But3) (27).34
Structrual Characterization of the Dimeric Organo
Group 13 Metal Oxide and Sulfide. [Ar′GaE]2 (M/E )
Ga/O, 7; In/O, 8; Ga/S, 9; or In/S, 10). The compounds 7-10
have centrosymmetric, dimeric structures and feature low-
coordinate metals [coordination number ) 3] with a planar M2E2
core (Figures 1 and 2). The twinned crystals of compound 9
contained four independent molecules within one unit cell.
Selected bond lengths and angles of 7-10 are provided in
Table 2.
The M2O2 arrays in 7 and 8 are almost perfectly square
(internal ring angles are within ca. 1° of 90°) with M-O
In contrast to the square planar M2O2 arrays in 7 and 8, 9
and 10 have planar M2S2 units with much greater angular
disparities within the rings. There are acute M-S-M angles
[9, 79.3° avg.; 10, 81.89(3)°] and angles almost 20° wider at
the metals: S-M-S angles are 100.71° avg. [9] and 98.11(3)°
[10]. The four independent molecules in crystals of 9 have
(32) Green, M. L. H.; Mountford, P.; Smout, G. J.; Speel, S. R.
Polyhedron 1990, 9, 2763.
(33) (a) Petrie, M. A.; Olmstead, M. M.; Power, P. P. J. Am. Chem.
Soc. 1991, 113, 8704. (b) Linti, G.; Frey, R.; Polborn, K. Chem. Ber. 1994,
127, 1387. (c) Cleaver, W. M.; Barron, A. R. Organometallics 1993, 12,
1001.
(34) Coombs, N. D.; Bunn, N. R.; Kays, D. L.; Day, J. K.; Ooi, L.-L.;
Aldridge, S. Inorg. Chim. Acta 2006, 359, 3693.
Figure 1. Thermal ellipsoid (50%) drawing of 7. Hydrogen atoms
are not shown. Dihedral angles between Ga2O2 plane and C(1)-C(6)
ring ) 88.5°.

Chalcogenide/Chalcogenolate Structural Isomers
Organometallics, Vol. 28, No. 8, 2009 2517
Table 2. Selected Structural Data for 7-10
7
8 · 0.5C6H14
9 · 4C6H6
10 · 2C7H8
M-E (Å)
1.830(3)
1.826(3)
2.553(3)
2.0258(13)
2.2181(10)
2.2162(10)
2.8305(9)
1.940(3)
2.4123(13)
2.4059(13)
3.1577(8)
2.140(4)
81.89(3)
98.11(3)
131.08(12)
130.81(12)
123.0(3)
M · · · M (Å)
2.8882(4)
2.107(2)
90.94(8)
89.06(8)
135.47(4)
C(ipso)-M (Å)
M-E-M (deg)
E-M-E (deg)
C(ipso)-M-E (deg)
1.944(4)
88.55(13)
91.45(13)
135.05(14)
133.39(15)
113.4(3)
79.33(4)
100.67(4)
128.27(10)
131.05(10)
116.5(2)
C(ortho)-C(ipso)-M (deg)
118.99(11)
126.5(3)
123.0(2)
115.8(3)
similar Ga-S bond lengths, and the average bond distance is
ca. 2.216 Å. These Ga-S bonds are shorter than those found
in structurally characterized, four-coordinate organogallium
sulfides, which have Ga-S distances in the range of ca.
2.25-2.27 Å; for example, in the dimer [RGaS]2 (R )
HC{(CMe)(2,6-Pri2C6H3N)}2, 4),9 ca. 2.23-2.25 Å in the trimers
[RGa(S)py]3(R ) But, 28;5c Me, 29;5d Et, 305d), ca. 2.35-2.40
Å in the cubane tetramers [RGaS]4 (R ) But, 315a,b Et2MeC,
32;5e Et3C, 33;5e (Me3Si)3C, 34;5h 2,2,6,6-tetramethylpiperidino,
355g or Cp(CO)Fe, 365f), ca. 2.32 to 2.40 Å in the hexamer
Structrual Characterization of the Dimeric Organo
Group 13 Metal Aryloxides and Thiolates. [Ar′EM]2 (E/
M ) O/In (16), O/Tl (17), S/In (18), or S/Tl (19)). Although
various attempts to synthesize [Ar′EGa]2 did not result in
isolation of the target compounds (see above), the indium
congeners 16 and 18 were obtained in good yield via trans-
metalation by the reaction of Ar′ELi and InCl. Compounds 16
and 18, together with 8 and 10, represent the first structurally
characterized isomeric pairs of organo group 13 metal/chalcogen
derivatives (Figures 3 and 4). Selected bond lengths and angles
of 16 and 18 as well as 17 and 19 are provided in Table 3.
[ButGaS]6 (37),5c and ca. 2.30 to 2.37 Å in heptamer [ButGaS]7
t
(38).5c The terminal sulfide complex TpBu 2GaS (3)11 also has
Unlike the quasi-isomeric pair of the gallium amide and imide
14 and 15, which are monomers, compounds 16 and 18 both
associate to form dimers with bridging indium atoms in the +1
oxidation state. The In · · · In separations of 3.598 and 4.673 Å
in 16 and 18 preclude any significant metal-metal interaction
and are a consequence of aryloxide and thiolate bridging. The
In · · · In separations may be compared to those in currently
known associated organoindium(I) compounds, which usually
have very weak In-In interactions and long In · · · In distances.
The In · · · In separation is 3.94-3.96 Å in hexameric [Cp*In]6
(47), where it is believed that the metal-metal distances are
dictated by the interactions of the six Cp* groups, which impose
a longer metal-metal separation, 4.07-4.17 Å, in its more
crowded gallium congener [Cp*Ga]6.39b In · · · In separations of
ca. 2.99-3.15 Å are observed in tetrameric [InC(SiMe2Et)3]4
(48),39g [InC(SiMe2Pri)3]4 (49),39g and [InC(SiMe3)3]4 (50),39d-f
and ca. 2.98-3.63 Å in dimeric Ar′InInAr′ (51),22 [In{η5-
C5(CH2Ph)5}]2 (52),39c and {In[(NMesCMe)2CH]}2 (53).39h The
four-coordinate gallium centers; however, a significantly shorter
Ga-S distance of 2.093(2) Å was observed due to terminal
coordination of the sulfide and/or Ga-S multiple bond character.
The Ga-S distances in 9 are within the range 2.20-2.27 Å
found in other low coordinate Ga-S species, for example,
{[(SiMe3)2CH]2Ga}2S, (39),35a (2,4,6-tBu3-C6H2S)3Ga (40),35b
(2,4,6-But3-C6H2S)2GaSMe (41),35b and BunGa(SC6H2-2,4,6-
But3)2 (42).35c The In-S bonds of 2.4123(13) and 2.4059(13)
Å in 10 display similar effects. They are substantially shorter
than the In-S bond length range of 2.54-2.58 Å in the
tetrameric [RInS]4 (R ) (SiMe3)3C, 43;7b MoCp(CO)3, 44;7a
or FeCp(CO)2, 457a), in which the indiums are four-coordinate,
but they are similar to the 2.39-2.40 Å in the three-coordinate
indium thiolate species (2,4,6-tBu3-C6H2S)3In (46).36
The M-E-M angles of 79.33(4) and 81.89(3)° in 9 and 10
are ca. 8 and 7° narrower than 88.55(13) and 90.94(8)° in 7
and 8. Greater bending at sulfur is expected and is consistent
with generally narrower angles in divalent sulfur compounds
[92° in SH2 vs 104.5° in H2O].37 The M · · · M separations of
2.553(1), 2.8882(4), 2.8276 (avg.), and 3.1577(8) Å in 7-10
are the shortest observed for [RME]n species2,4-7,9,10 and only
slightly exceed the sum of their covalent radii.38 However, the
short M · · · M separations do not imply significant M · · · M
bonding since the metals have considerable cationic character
affording effective ionic radii which are considerably smaller
than covalent radii. The faces of the M2E2 arrays are shielded
by the flanking C6H3-2,6-Pri2 groups of the Ar′ ligand, which
are orientated above and below the M2E2 plane. This is further
quantified by the dihedral angle between the M2E2 rings and
central Ph ring which are 88.5 (7), 85.93 (8), 76.1-86.8 (9),
and 85.93° (10). The protection by the steric encumbering
ligands thus stabilizes the dimeric forms of 7-10.
(35) (a) Uhl, W.; Gerding, R.; Hahn, I.; Pohl, S.; Saak, W.; Reuter, H.
Polyhedron 1996, 15, 3987. (b) Ruhlandt-Senge, K.; Power, P. P. Inorg.
Chem. 1991, 30, 2633. (c) Wehmschulte, R. J.; Ruhlandt-Senge, K.; Power,
P. P. Inorg. Chem. 1995, 34, 2593.
(36) Ruhlandt-Senge, K.; Power, P. P. Inorg. Chem. 1993, 32, 3478.
(37) Greenwood, N. N.; Earnshaw, A. Chemistry of the Elements;
Butterworth-Heinemann: Oxford, 1994.
(38) Emsley, J. The Elements, 2nd ed.; Oxford University Press: New
York, 1981. For example, the ionic radii for Ga+ and Ga3+ are 1.13 and
0.62 Å, whereas the covalent radius is 1.25 Å. The corresponding data for
In+, In3+, and In are 0.92, 1.32, and 1.5 Å.
Figure 3. Thermal ellipsoid (50%) drawing of 16. Hydrogen
atoms are not shown. Dihedral angles between In2O2 plane and
C(1)-C(6) ring ) 57.0°, C6H3-2,6-Pri2(centroid)-In range )
3.099-3.134 Å.

2518 Organometallics, Vol. 28, No. 8, 2009
Zhu et al.
Table 3. Selected Structural Data for 16-19
16
17
18 · 3.5C7H8
19 · 2.4C7H8
M(1)-E(1) (Å)
M(1)-E(2) (Å)
M(2)-E(1) (Å)
M(2)-E(2) (Å)
C(1)-E(1) (Å)
C(1)-E(2) (Å)
M(1)-E(1)-M(2) (deg)
M(1)-E(2)-M(2) (deg)
E(1)-M(1)-E(2) (deg)
E(1)-M(2)-E(2) (deg)
C(1)-E(1)-M(1) (deg)
C(1)-E(1)-M(2) (deg)
C(2)-C(1)-E(1) (deg)
C(32)-C(31)-E(1) (deg)
2.3216(15)
2.3533(16)
2.3420(16)
2.3147(15)
1.357(2)
1.356(3)
100.99(6)
100.86(6)
78.89(5)
79.26(5)
133.49(13)
116.56(13)
120.41(19)
121.0(2)
2.579(3)
2.8434(14)
2.7987(14)
2.8069(14)
2.8261(15)
1.772(5)
2.913(13)
2.884(3)
2.884(3)
2.908(3)
1.760(12)
1.763(11)
111.98(11)
112.14(10)
67.83(9)
67.91(9)
122.9(4)
121.2(4)
120.9(9)
121.0(9)
2.540(3)a
1.322(5)
96.75(11)
81.84(11)
1.765(5)
111.33(4)
112.10(5)
68.01(4)
68.14(4)
129.6(3)
122.3(5)a
121.7(4)
121.90(17)
120.19(17)
120.4(4)
120.5(4)
a Crytals of 13 have an inversion center, thus it generates E(1A) as E(2) and M(1A) as M(2).
In-O bond lengths in 16 [2.3216(15), 2.3533(16), 2.3420(16),
and 2.3147(15) Å] are similar to the 2.320 Å (avg.) in the
molecular compound [2,4,6-(CF3)3-C6H2OIn]2 (11)18a but are
considerably shorter than the 2.58-2.65 Å in the In(I) triflate
complex [CF3SO3In]2 (12).18b Compound 16 has In-O bonds
ca. 0.3 Å longer than the 2.026(1) Å observed in 8, which is,
most probably, a consequence of the lower metal oxidation state
in 16. Compound 18 is the first structurally authenticated
organoindium(I) thiolate and has In-S bonds in the range of
2.80-2.84 Å. These are ca. 0.4 Å longer than the 2.4123(13)
and 2.4059(13) Å in 7, as a consequence of the lower oxidation
state and reduced ionic contribution to the bond strength.
Although the O2In2 array of 16 is planar with acute O-In-O
angles of 78.89(5) and 79.26(5)° and In-O-In angles of
100.99(6) and 100.86(6)°, the S2In2 array of 18 is slightly folded
[the dihedral angle between In(1)-S(1)-In(2) and In(1)-
S(2)-In(2) ) 171.4°] with highly acute S-In-S angles of
68.01(4) and 68.14(4)° and obtuse In-S-In angles of 111.33(5)
and 112.10(5)°. The In(I) centers in 16 and 18 both feature close
contacts with the flanking rings of Ar′. In 16, In(I) metals η6-
coordinate to one flanking aryl ring of each Ar′ ligand with
In-C6H3-2,6-Pri2(centroid) distances ranging from 3.099 to
3.134 Å, while in 18, In(I) metals symmetrically η6-coordinate
to both flanking aryl rings on each Ar′ ligand with In-C6H3-
2,6-Pri2(centroid) distances that range from 3.144 to 3.177 Å.
These In-arene distances are longer than ca. 2.83-2.89 Å
spanned by [(1,3,5-Me3-C6H2)2In][InBr4] (54)40a and shorter than
3.490(4) and 3.325(4) Å in [(η6-C7H8)In(µ-η5-C5Me5)In(η6-
C7H8)][(C6F5)3BO(H)B(C6F5)3] (55),40b indicating that both 16
and 18 have a moderate In-arene interaction. The coordination
geometry of the sulfurs in 18 is nearly planar [Σ°S(1) ) 353.42;
Σ°S(2) ) 357.55]. This might be a result of the large Ar′
substituent which enforces a nearly planar environment at sulfur
upon dimerization. Greater bending at sulfur with the E-In-E
and In-E-C angles of 68.1 (avg.) and 120.5° (avg.) in 18 is
also observed, which are both ca. 11° smaller than those in 16.
The related dimeric terphenyl thiolate alkali metal salts
(Ar*SM)2 (Ar* ) C6H3-2,6-(C6H2-2,4,6-Pri3)2; M ) K-Cs) with
similar S2M2 cores also feature flanking ring-metal ion interac-
tions, which are determined by ionic sizes. The coordination
geometry of the thiolato sulfurs varies from pyramidal to nearly
planar on descending the group.41
Compounds 17 and 19 are a part of a growing class of
structurally characterized Tl(I) derivatives of RE- (R ) alkyl,
aryl, or related species; E ) O and S; Figures 5 and 6). Tl(I)
compounds with the formula of (ROTl)n or (RSTl)n have been
shown to mainly aggregate as coordination polymers17i,k,42 or
oligomers.17f,42a,43,44 The Tl-E bond lengths of 2.540(3) and
2.579(3) Å in 17 and 2.913(3), 2.884(3), 2.884(3), and 2.908(3)
Å in 19 are within the range of 2.460-2.748 Å spanned by the
previous reported alkoxide dimers (ROTl)2 (R ) NdC(CN)-
COPh, 56;43e (3-But-pyrazolyl)3SO2, 57;43g C6H2-2,4,6-(CF3)3,
58;43b and C6H5-2-(C6H5-2-OH), 5943f) and ca. 2.880-2.903 Å
in the thiolate dimer [(ButO)3STl]2 (60).44 The Tl2E2 arrays of
17 and 19 are slightly folded (17, 160.6°; 19, 175.2°) with acute
(39) (a) Beachley, O. T., Jr.; Churchill, M. R.; Fettinger, J. C.; Pazik,
J. C.; Victoriano, L. J. Am. Chem. Soc. 1986, 108, 4666. (b) Schumann,
H.; Janiak, C.; Goerlitz, F.; Loebel, J.; Dietrich, A. J. Organomet. Chem.
1989, 363, 243. (c) Loos, D.; Baum, E.; Ecker, A.; Schno¨ckel, H.; Downs,
A. J. Angew. Chem., Int. Ed. Engl. 1997, 36, 860. (d) Schumann, H.; Janiak,
C.; Goerlitz, F.; Loebel, J.; Dietrich, A. J. Organomet. Chem. 1989, 363,
243. (e) Schluter, R. D.; Cowley, A. H.; Atwood, D. A.; Jones, R. A.;
Atwood, J. L. J. Coord. Chem. 1993, 30, 25. (f) Uhl, W.; Graupner, R.;
Layh, M.; Schuetz, U. J. Organomet. Chem. 1995, 493, C1. (g) Haaland,
A.; Martinsen, K.-G.; Volden, H. V.; Kaim, W.; Waldhoer, E.; Uhl, W.;
Schuetz, U. Organometallics 1996, 15, 1146. (h) Uhl, W.; Jantschak, A.;
Saak, W.; Kaupp, M.; Wartchow, R. Organometallics 1998, 17, 5009. (i)
Hill, M. S.; Hitchcock, P. B.; Pongtavornpinyo, R. Angew. Chem., Int. Ed.
2005, 44, 4231.
(40) (a) Ebenhoch, J.; Miiller, G.; Riede, J.; Schmidbaur, H. Angew.
Chem., Int. Ed. Engl. 1984, 23, 386. (b) Cowley, A. H.; Macdonald, C. L. B.;
Silverman, J. S.; Gorden, J. D.; Voigt, A. Chem. Commun. 2001, 175.
(41) Niemeyer, M.; Power, P. P. Inorg. Chem. 1996, 35, 7264.
(42) (a) Krebs, B.; Broemmelhaus, A. Z. Anorg. Allg. Chem. 1991, 595,
167. (b) Labahn, D.; Pohl, E.; Herbst-Irmer, R.; Stalke, D.; Roesky, H. W.;
Sheldrick, G. M. Chem. Ber. 1991, 124, 1127. (c) Krebs, B.; Brommelhaus,
A.; Kersting, B.; Nienhaus, M. Eur. J. Solid State Inorg. Chem. 1992, 29,
167.
Figure 4. Thermal ellipsoid (50%) drawing of 18. Hydrogen atoms
are not shown. Fold angle of In2S2 [defined as dihedral angle
between In(1)-S(1)-In(2) and In(1)-S(2)-In(2)] ) 171.4°, C6H3-
2,6-Pri2(centroid)-In range ) 3.144-3.177 Å.

Chalcogenide/Chalcogenolate Structural Isomers
Organometallics, Vol. 28, No. 8, 2009 2519
Figure 5. Thermal ellipsoid (50%) drawing of 17. Hydrogen atoms
are not shown. Fold angle of Tl2O2 [defined as dihedral angle
between Tl(1)-O(1)-Tl(1A) and Tl(1)-O(1A)-Tl(1A)] ) 160.8°,
C6H3-2,6-Pri2(centroid)-Tl range ) 3.075-3.154 Å.
Figure 6. Thermal ellipsoid (30%) drawing of 19. Hydrogen atoms
are not shown. Fold angle of Tl2S2 [defined as dihedral angle
between Tl(1)-S(1)-Tl(2) and Tl(1)-S(2)-Tl(2)] ) 175.2°, C6H3-
2,6-Pri2(centroid)-Tl range ) 3.108-3.180 Å.
E-Tl-E angles of 81.84(11)° in 17 and 67.87(9)° (avg.) in 19
as well as obtuse Tl-E-Tl angles of 96.75(11)° in 17 and
112.06(11)° (avg.) in 19. The Tl(I) centers in 17 and 19 also
feature close contacts with the flanking rings of Ar′ (Tl-
(centroid) distances range from 3.075 to 3.154 Å in 17 to
3.108-3.180 Å in 19. These Tl-arene distances are similar to
ca. 2.94-3.03 and 2.94-3.35 Å spanned by [Mes2TlOTeF5]2
(63),45a {[Mes2Tl][AlCl4]}2 (62),45b and [(Mes)6Tl4(GaBr4)4]
(61).45c Furthermore, the Tl-arene contacts in 17 are preserved
in solution as shown by 13C NMR spectroscopy which had
13C-Tl coupling to the ortho (52 Hz), meta (70 Hz), and para-
carbons (37 Hz) of the dipp ring. The poor solubility of 19 in
C6D6 and C7D8 prevented collection of usable 13C NMR data,
and the Tl-C coupling constants could not be extracted. A
nearly planar coordination geometry of the sulfurs in 19 is also
observed [Σ°S(1) ) 357.2; Σ°S(2) ) 354.4] with a greater
bending angle [the E-Tl-E and Tl-E-C angles in 19 are ca.
14 and 10° smaller than those in 17].
Conclusion
In summary, dimeric arylgallium/indium chalcogenides 7-10
of formula [Ar′ME]2 (M ) Ga or In; E ) O or S) were
synthesized and fully characterized. They feature three-
coordinate, +3 oxidation state metal centers with planar M2E2
cores. Low oxidation heavier group 13/group 16 chalcogenolate
isomers 16-19 of formula [Ar′EM]2 (M ) In or Tl; E ) O or
S) were also synthesized and fully characterized. The In +1
compounds [Ar′EIn]2 (O, 17; S, 19) together, with the In +3
species [Ar′InE]2 (O, 8; S, 10), represent the first structurally
characterized isomeric pairs of organo group 13 metal/chalcogen
derivatives. The difficulties encountered in synthesizing the
Ga(I) chalcogenolates and Tl(III) chalcogenides reflect the
increasing stabilization of the s-valence electrons descending
the group.
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K. V. DopoVidi Akademii Nauk Ukraini 1994, 127. (f) El-Hadad, A. A.;
Kickham, J. E.; Loeb, S. J.; Taricani, L.; Tuck, D. G. Inorg. Chem. 1995,
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Acknowledgment. We thank the National Science Foun-
dation (CHE-0641020) for financial support. Z.Z. thanks Dr.
Eric Rivard for the helpful discussions.
Supporting Information Available: X-ray data (CIFs) for 7-10
and 16-19 plus thermal ellipsoidal plots of 8 and 9. This material
is available free of charge via the Internet at http://pubs.acs.org.
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