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Infrared spectra of alkoxy-bridged tin complexes
SHORT COJIVCSIC_~TIOSS
95
L 11. D_ RACSCH.E_ 0. FISCHER AXD H_ GRCBERT. J_ dnt. Chem. SOL. Sr? (1960) 76. E. \\‘_~EUSS ASD K. KODA. J_ O~~a,zotnetoZ. Chem., 4 (1965) 475s E. W. XEUSE ASD I(. KODA. BUZZ. Chem. Sot. (Japan). in press. + E. XX’.>-ECSB ASD E. QCO. BUZZ. Chon. Sot. (Japazx). in press5 E. \\-\‘.SECSE _GD D. S. TRIFAS. _4hf~. ofpaprrsp~eseafcd aZr,&h ~Sat~onaZ_~f&?f~n,q _AIII. Chsm. Sot.. September 1964. 6 E_ \i‘. XECSE _&SD Ii_ KoDA. J_ PoIpmr Sci.. submitted for publication. 7 E. A. HILL &SD J. H. RICH_+RDS, J_ Am. Chem. Sac.. S3 (1961) 3S.+o_ S J_ H. RICHARDS. hoc. Puint Res. Imt., So. 31 (1964) ‘$33. 13
9 T. Ktx-ASA, D. E. Bc~rrrz ASD G. HOH. J_ IO L.FRIEDH_~s,_\_
P. IRSA ASD
Received
December
Infrared
spectra
Am.
Chcnr. SOL. Sz (1960)
G.\\'rr~~ssos,J__~rn_C~cn~.Soc..
$I’_
77 (1955) 36%.
3rd. 1965
of alkoxy-bridged
tin
complexes
Prex-iousl- w-e have reported1 the preparation (acetylacetonato)tin dihalides ~(CH,0)(C5H~OJSnS,~2
ba& of their infrared spectra and rnokcular g-ted a probable configuration (I)_
weight
and
properties
of methosy-
(ST=‘; Cl, Br, I) and on the determinations we have sug-
(1:
In this paper, the infrared spectra in the 1600-400 cm-r region of these compleses and some nex akykrbstituted compounds of (I), L(CH30) (C5HiO~Sn>XI,, x-ill be described_ These complexes four-membered
ring Sn@Sn.
belon, m to a series of typical compounds
In the chemistry
of organotin
compounds,
having a this is a
structural feature of considerable importance2. The infrared spectra of these complexes
are rather simple, and these reAts will be rueful in the interpretation of more complicated spectra such as those of the dimeric tetraalk>-1-1,x-disubstituted distannosanez, which are known to have the four-membered ring3. The spectra of these compkses are almost identical to those of the corresponding except for additional strong bands appearing at bis(acetylacetonato)tin complex?? rozo-o7o and 53o-$0 cm-r. The former band is assigned to a perturbed H&-O stretching vibration and the latter to a ring vibration of the Sn-0 four-membered ring. The frequencies of these two bands are listed in Table I. Fig. I shows correlations of these bands with the sum of the Harnmett’s constant5 (T* of the substituents S and Y, and it is clear that there are linear relationships between o* and the wave numbers of these two bands. It is seen that the weaker the H&-O bond, the stronger is the
coordination of 3 metho+group to tin to form a rigid S-0 four membered ring. The reufts indicate that the inductive effect of substituents attacked to the tin atom plays a predominant role in the ckan ~=r’of infrared frequencies of tke bonds described above_ Thesame is true for tkeskift of frequencie.; due to the acetyIacetonato groups attac!wd
to tin’.
_~i=~~o.t~jcrcz:_r-lacr:o7:afo)-ta-brr~~~fi,rclrlorirfi.
metzZ (0.45
To a methanol
solution
of sodium
gj znd acetylacetone (I g) n-butyltin trichloride (~3 g) was added and
the mixture was heated at reflux for a few minutes. Z-odium chloride was titered immediately from the hot solution. -1 white crys.talline precipitate formed ,qdualI_\as the titrate cooled. AnaI_vticzl data are skown in Table 2.
SHORT COMXGSIC;\TIOXS
97
TABLE 2 ~IETROS~~(ACE~L;\CEiOS.~TO)_ILKYLTIS
1’
CH, CH,
C,Hs “-C,II,
Reaction
_x-
CI Br BLCl
31.p. (‘C)
ISS (dec.) 187 (dec.)
173-6 (dec.) 99-109
r(CH,O)iC,H,O,)Sn‘l’SI,
HALIDES:
0;
c
Fotrnd Culcd.
Found
ZS_Ii_ 2+_$s
2S.09 r+#i
4-30
35.15
35.15
26.99 2626
of p(dimethylamino)bromobenrene
“& _Y
ObH
Fcrrnd
Calcd.
4-3s
3S1 3.81 -(_I7 a.23 5.67 5.61
C&d.
II-97
11.g
10.g1
IO-39
“320 23.23 21.25 22.34
with “activated”
magnesium
It has been showr b>- Ehrlich and Sachs 1 that p-(dimethyknnino)bromobenzene Could react with magnesium powder if initial!>- activated by bromoethane (entrainment method). Subsequently. this method for the preparation of $-(dirnethylaminojphenylmagnesium bromide lx-asemployed by sex-era1other investigators2-6. As a rtiult of the unimpressk-e !-ields of this Grignard reagent, how-ever. the lithium reagent is usually preferred. Recently, Owen: described the preparation of this Grignard reagent in tetrahydrofuran (THF) after initiation with ethyl iodide or iodine. In regard to another problem in this laboratory, a procedure has been discovered for the activation of magnesium turnings such that the resultant “activated” magnesium can be caused to react completely with $-(dimethykmino)bromobenzene in refiusing tetrahydrofuran -zdJmrt the aid of an initiation agent such as iodine or an entrainment reagent such as a haloalkane. The facile actix-ation procedure invol\-es the one day (or longer) room temperature mechanical stirring of magnesium tumine in a nitrogen atmosphere (to prevent aside formation of the resultant grey-biack, tineIy divided magnesium). -4ddition of $-(dimethylamino)bromobenzene in THF to such magnesium with gentle reflus of the THF results in a black solution with compIete or nearly complete reaction of the magnesium. J_ Or,paxometal.
Chem.,
6 (x966)
9799
95
L 11. D_ RACSCH.E_ 0. FISCHER AXD H_ GRCBERT. J_ dnt. Chem. SOL. Sr? (1960) 76. E. \\‘_~EUSS ASD K. KODA. J_ O~~a,zotnetoZ. Chem., 4 (1965) 475s E. W. XEUSE ASD I(. KODA. BUZZ. Chem. Sot. (Japan). in press. + E. XX’.>-ECSB ASD E. QCO. BUZZ. Chon. Sot. (Japazx). in press5 E. \\-\‘.SECSE _GD D. S. TRIFAS. _4hf~. ofpaprrsp~eseafcd aZr,&h ~Sat~onaZ_~f&?f~n,q _AIII. Chsm. Sot.. September 1964. 6 E_ \i‘. XECSE _&SD Ii_ KoDA. J_ PoIpmr Sci.. submitted for publication. 7 E. A. HILL &SD J. H. RICH_+RDS, J_ Am. Chem. Sac.. S3 (1961) 3S.+o_ S J_ H. RICHARDS. hoc. Puint Res. Imt., So. 31 (1964) ‘$33. 13
9 T. Ktx-ASA, D. E. Bc~rrrz ASD G. HOH. J_ IO L.FRIEDH_~s,_\_
P. IRSA ASD
Received
December
Infrared
spectra
Am.
Chcnr. SOL. Sz (1960)
G.\\'rr~~ssos,J__~rn_C~cn~.Soc..
$I’_
77 (1955) 36%.
3rd. 1965
of alkoxy-bridged
tin
complexes
Prex-iousl- w-e have reported1 the preparation (acetylacetonato)tin dihalides ~(CH,0)(C5H~OJSnS,~2
ba& of their infrared spectra and rnokcular g-ted a probable configuration (I)_
weight
and
properties
of methosy-
(ST=‘; Cl, Br, I) and on the determinations we have sug-
(1:
In this paper, the infrared spectra in the 1600-400 cm-r region of these compleses and some nex akykrbstituted compounds of (I), L(CH30) (C5HiO~Sn>XI,, x-ill be described_ These complexes four-membered
ring Sn@Sn.
belon, m to a series of typical compounds
In the chemistry
of organotin
compounds,
having a this is a
structural feature of considerable importance2. The infrared spectra of these complexes
are rather simple, and these reAts will be rueful in the interpretation of more complicated spectra such as those of the dimeric tetraalk>-1-1,x-disubstituted distannosanez, which are known to have the four-membered ring3. The spectra of these compkses are almost identical to those of the corresponding except for additional strong bands appearing at bis(acetylacetonato)tin complex?? rozo-o7o and 53o-$0 cm-r. The former band is assigned to a perturbed H&-O stretching vibration and the latter to a ring vibration of the Sn-0 four-membered ring. The frequencies of these two bands are listed in Table I. Fig. I shows correlations of these bands with the sum of the Harnmett’s constant5 (T* of the substituents S and Y, and it is clear that there are linear relationships between o* and the wave numbers of these two bands. It is seen that the weaker the H&-O bond, the stronger is the
coordination of 3 metho+group to tin to form a rigid S-0 four membered ring. The reufts indicate that the inductive effect of substituents attacked to the tin atom plays a predominant role in the ckan ~=r’of infrared frequencies of tke bonds described above_ Thesame is true for tkeskift of frequencie.; due to the acetyIacetonato groups attac!wd
to tin’.
_~i=~~o.t~jcrcz:_r-lacr:o7:afo)-ta-brr~~~fi,rclrlorirfi.
metzZ (0.45
To a methanol
solution
of sodium
gj znd acetylacetone (I g) n-butyltin trichloride (~3 g) was added and
the mixture was heated at reflux for a few minutes. Z-odium chloride was titered immediately from the hot solution. -1 white crys.talline precipitate formed ,qdualI_\as the titrate cooled. AnaI_vticzl data are skown in Table 2.
SHORT COMXGSIC;\TIOXS
97
TABLE 2 ~IETROS~~(ACE~L;\CEiOS.~TO)_ILKYLTIS
1’
CH, CH,
C,Hs “-C,II,
Reaction
_x-
CI Br BLCl
31.p. (‘C)
ISS (dec.) 187 (dec.)
173-6 (dec.) 99-109
r(CH,O)iC,H,O,)Sn‘l’SI,
HALIDES:
0;
c
Fotrnd Culcd.
Found
ZS_Ii_ 2+_$s
2S.09 r+#i
4-30
35.15
35.15
26.99 2626
of p(dimethylamino)bromobenrene
“& _Y
ObH
Fcrrnd
Calcd.
4-3s
3S1 3.81 -(_I7 a.23 5.67 5.61
C&d.
II-97
11.g
10.g1
IO-39
“320 23.23 21.25 22.34
with “activated”
magnesium
It has been showr b>- Ehrlich and Sachs 1 that p-(dimethyknnino)bromobenzene Could react with magnesium powder if initial!>- activated by bromoethane (entrainment method). Subsequently. this method for the preparation of $-(dirnethylaminojphenylmagnesium bromide lx-asemployed by sex-era1other investigators2-6. As a rtiult of the unimpressk-e !-ields of this Grignard reagent, how-ever. the lithium reagent is usually preferred. Recently, Owen: described the preparation of this Grignard reagent in tetrahydrofuran (THF) after initiation with ethyl iodide or iodine. In regard to another problem in this laboratory, a procedure has been discovered for the activation of magnesium turnings such that the resultant “activated” magnesium can be caused to react completely with $-(dimethykmino)bromobenzene in refiusing tetrahydrofuran -zdJmrt the aid of an initiation agent such as iodine or an entrainment reagent such as a haloalkane. The facile actix-ation procedure invol\-es the one day (or longer) room temperature mechanical stirring of magnesium tumine in a nitrogen atmosphere (to prevent aside formation of the resultant grey-biack, tineIy divided magnesium). -4ddition of $-(dimethylamino)bromobenzene in THF to such magnesium with gentle reflus of the THF results in a black solution with compIete or nearly complete reaction of the magnesium. J_ Or,paxometal.
Chem.,
6 (x966)
9799