Chemistry of bis(.eta.6-naphthalene)chromium ligand exchange reactions: synthesis and characterization of poly[.mu.-.eta.6,.eta.6-naphthalene)chromium]

1988 ◽  
Vol 7 (9) ◽  
pp. 1945-1948 ◽  
Author(s):  
B. F. Bush ◽  
J. J. Lagowski
Keyword(s):  
Ligand Exchange ◽  
Synthesis And Characterization ◽  
Exchange Reactions

Synthesis and Characterization of Strontium Bis(N-isopropylanilide) and Comparison with the Lighter Magnesium and Calcium Congeners

2013 ◽  
Vol 68 (5-6) ◽  
pp. 518-532 ◽  
Author(s):  
Claas Loh ◽  
Carsten Glock ◽  
Steffen Ziemann ◽  
Helmar Görls ◽  
Sven Krieck ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Synthesis And Characterization ◽  
Alkaline Earth Metal ◽  
Similar Reaction ◽  
Exchange Reactions ◽  
Metathesis Reaction ◽  
Short Contacts

The metathesis reaction of strontium diiodide [(thf)5SrI2] with K[N(Ph)iPr] in THF yields [(thf)4Sr{N(Ph)iPr}2] (1). Ligand exchange reactions with 1,2-dimethoxyethane (DME), tetramethylethylenediamine (TMEDA), and pentamethyldiethylenetriamine (PMDETA) allow the isolation of the corresponding adducts [(dme)2Sr{N(Ph)iPr}2] (2), [(tmeda)(thf)Sr{N(Ph)iPr}2] (3) and [(pmdeta)Sr{N(Ph)iPr}2] (4), respectively. Magnesiation of N-isopropylaniline with dibutylmagnesium in THF leads to the formation of [(thf)2Mg{N(Ph)iPr}2] (5). A similar reaction in TMEDA gives nearly insoluble crystalline [(tmeda)Mg{N(Ph)iPr}2] (7), whereas the mother liquor contains heteroleptic [(tmeda)(nBu)Mg{N(Ph)iPr}] (6). Magnesiation of N-isopropylaniline in 2,2,5,5-tetramethyltetrahydrofuran (Me4thf) yields [(Me4thf)Mg{N(Ph)iPr}2] (8) with a threecoordinate metal center. In hydrocarbons this complex loses the bulky ether base, and the solvent-free dimer [Mg{N(Ph)iPr}2]2 (9) can be isolated. Reaction of this complex with 1,2- dimethoxyethane or metalation of N-isopropylaniline with dibutylmagnesium in DME yield the dme adduct, [(dme)Mg{N(Ph)iPr}2] (10). The crystal structures show that the nitrogen atoms of the magnesium-bound N-isopropylanilide ions are in planar environments whereas strontium-bound N-isopropylanilide ions show rather short contacts between the alkaline earth metal and the ipsocarbon atoms of the phenyl groups leading to a pyramidalization of the coordination of the nitrogen atoms

scholarly journals Synthesis and Characterization of Aza-Trimetalla Tetrahedranes

1996 ◽  
Vol 51 (11) ◽  
pp. 1621-1626 ◽  
Author(s):  
Max Herberhold ◽  
Uwe Bertholdt ◽  
Bernd Wrackmeyer
Keyword(s):  
Nitrogen Atom ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Synthesis And Characterization ◽  
Exchange Reactions ◽  
H Nmr ◽  
A Minor

The sulfimide complex Fe2(CO)6(μ-SNH) (1) reacts with Co2(CO)8 to form a 1:1 mixture of the known clusters FeCo2(CO)9(μ3-S) (2) and FeCo2(CO)9(μ3-NH) (3). The azatetrahedrane 3 may be used as a precursor for the synthesis of the new aza-trimetalla tetrahedranes Fe2Co(CO)9(μ-H)(μ3-NH) (5), CpMoFeCo(CO)8(μ3-NH) (6), CpNiFeCo(CO)6(μ3-NH) (7) and (CpNi)2Fe(CO)3(μ3-NH) (8) which were obtained from exchange reactions of 3 with Na2[Fe(CO)4], Na[CpMo(CO)3] and [CpNi(CO)]2. However, the reactions of 3 with Na2[Fe(CO)4] and Fe3(CO)12 gave Fe3(CO)9(μ-H)2(μ3-NH) (9) only as a minor product in addition to large amounts of Fe3(CO)9(μ-H)2(μ3-S) (10). The 1H NMR spectra of 3 and 5 - 9 show a broadened triplet for the NH proton between δ(1H) 8.21 and 9.53. Chemical shifts δ(14N) were determined most efficiently by heteronuclear 1H {14N} double resonance experiments. The δ(14N) values for aza-trimetalla tetrahedranes (-180 to -202) indicate delocalized bonding between the μ3-bridging nitrogen atom and the metal triangle.

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