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Crystal Structure of Bis(cyclooctatetraene)titanium.

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The pentapeptide was electrophoretically and chromatographically homogeneous and on total hydrolysis gave the
amino acids Phe. Glu, Gly. Leu, and Tyr in the proportions
0.98 : 1.13 : 1.00 : 1.07 : 0.89 (D. Georgopoulos). In the
plastein reactionr31 with pepsin, a 25-mg sample gave 14 mg
(60%) of water-insoluble polypeptide mixture.
Paper electrophoresis at p H 6.5 separated the blocked intermediate peptides into the four expected constituents (2carboxy-3-nitrobenzoyl derivatives of Phe, Glu-Phe, GlyGlu-Phe, and Leu-Gly-Glu-Phe), which appeared with
approximately equal intensity on development with the tertbutyl hypochlorite-tolidine reagent 141.
Received: August 4, 1969
[Z 67 IE]
German version: Angew. Chem. 81. 782 (1969)
[*I Prof. Dr. Th. Wieland, Dr. Chr. Birr, and
DipLChem. H. Wissenbach
Max-Planck-Institut fur Medizinische Forschung,
Abteilung Chemie
69 Heidelberg, Jahnstrasse 29 (Germany)
[l] Part 43 of Peptide Syntheses. This work was supported by the
Deutsche Forschungsgemeinschaft. - Part 42: Chr. Birr, W.Lochinger, and T. Wieland, Liebigs Ann. Chem., in press.
[2] R . B. Merrifield, J. Amer. chem. SOC.85, 2149 (1963); Th.
Wieland, Chr. Birr, and F. Flor, Liebigs Ann. Chem., 727, 130
(1969).
131 H. Determann, K . Bonhard, R. Kohler, and Th. Wieland,
Helv. chim. Acta 46, 2498 (1963).
[4] R. H. Mazur, B. W. Ellis, and P. S . Cammarata, J. biol.
Chemistry 237, 1619 (1962).
The structure of the pyridines (3a)-(3c) can be established
on the basis of their IH-NMR spectra.
Received: August 8, 1969
[Z 69 JEJ
German version: Angew. Chem. XI, 785 (1969)
[*I Dr. E. Breitmaier and Prof. Dr. E. Bayer
Lehrstuhl fur Organische Chemie der Universitat
74 Tiibingen, Wilhelmstr. 33 (Germany)
[I] A . P . Skoldinow, T . V . Protopova, and V. T. Ktimko, USSRPat. 136351 (1961); Chem. Abstr. 56, 3359 (1962).
[2] E. Breitmaier, unpublished.
[3] N . Sperber, M . Sherlock, D. Papa, and D. Kendler, J. Amer.
chem. SOC.81, 704 (1959).
[4] A. Dornow and W. Schaeht, Chem. Ber. 82, 117 (1949).
[5] S. Tsushiina and S . Sudzuki, J. chem. SOC.Japan 64, 1295
(1943).
Crystal Structure of
Bis(cyc1ooctatetraene)titanium
By H. Dietrich and M. Soltwisch[*l
The violet T: complex bis(cyc1ooctatetraene)titanium synthesized by Breil and Wilke [ ' I crystallizes monoclinically in the
space group Pb(Cz) with a = 7.00, b = 12.26, c = 7.928,,
y = -114.85 O , V = 617 A3; 2 = 2,
= 1.378 gm/cm3.
The crystal structure was determined from X-ray diffraction
data recorded o n a counting-tube diffractonleter using filter~
ed C U Kradiation.
Single-step Synthesis of Pyridines from
3-Aminoacrolein and Carbonyl Compounds
By E . Breitmaier and E. Bayerr*]
3-Aminoacrolein ( I ) 21 cyclocondenses with carbonyl
compounds of type ( 2 ) to give pyridine derivatives of type
( 3 ) ; Rl and R2 may also be part of the ring.
H
Ref.
COCHj
CH3
Ethyl 2-methyl3-pyridinecarboxylate
3-AcetyI-2methylpyridine
5,6,7,8-Tetrahydroquinoline
107-108
50
104-105
55
98-
99 20
The cyclocondensation proceeds via a Schiff base - formed
between the amino group of ( I ) and the carbonyl group of
(2) - combined with a Knoevenagel reaction between the
formyl group of ( I j and the methyl group of (2).
The crystal is partially disordered. Apparently another
molecular form exists in which the nonplanar ring interacts
with the titanium atom via three carbon atoms only (shortest
Ti-C bond length 2.2 A). At present the discrepancy factor
is R = 10%.
Received: July 31, 1969
[ Z 70 IE]
German version: Angew. Chem. 81, 785 (1969)
[*] Dr. H. Dietrich and M. Soltwisch
General procedure:
Ammonium acetate (50mg) is added t o a mixture of 3aminoacrolein( l ) [1*21 (0.05 mole) and a carbonyl compound
(2) (0.06 mole) and the mixture is stirred under reflux for 12
hours at an oil-bath temperature of llO°C. The oily reaction
mixture is then poured into ether (100 ml) and the resulting
ether solution is dried with magnesium sulfate and filtered
under vacuum. The ether is evaporated off and the residue
is fractionated at 12 torr.
Angew. Chem. internat. Edit.
The molecule contains one planar and one boat shaped
cyclooctatetraene ring. The planar one (C-C bond length
1.41 & 0.02 A[2J) is symmetrically attached to the titanium
atom (all Ti-C bond lengths 2.32 0.02 A[21), while the
nonplanar ring is bonded to the titanium atom via four carbon atoms only. In the Figure the two shorter Ti-C bond
lengths (2.2 8, each) are marked by full lines, the two longer
ones (2.5 8, each) by broken lines. The coordination of the
titanium is thus very similar t o that in tris(cyc1ooctatetraene)dititanium[lv31, in which, however, the two shortest Ti-C
bonds to the non planar ring are about 0.1 A longer.
/
Vol. 8 (1969) J No. I0
Fritz-Haber-Institut der Max-Planck-Gesellschaft
1 Berlin 33, Faradayweg 4-6 (Germany)
[l] H. Breiland G. Wilke, Angew. Chem. 78,942 (1966); Angew.
Chem. internat. Edit. 5, 898 (1966). We thank Prof. Wilke for
supplying the bis(cyc1ooctatetraene)titanium crystals.
[2] 20 is given as the limit of error.
131 H . Dietrich and H. Dierks, Angew. Chem. 78, 943 (1966);
Angew. Chem. internat. Edit. 5, 899 (1966); H. Dierks and
H . Dietrich, Acta crystallogr. B 24, 58 (1968).
765
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