Transition-metal-substituted diphosphenes. 21. [2 + 2] Cycloaddition of a diphosphene to maleimide and N-methylmaleimide. X-ray structure analysis of a 4,5-diphospha-2-azabicyclo[3.2.0]hepta-1,3-dione

1991 ◽  
Vol 10 (4) ◽  
pp. 1130-1135 ◽  
Author(s):  
Lothar. Weber ◽  
Matthias. Frebel ◽  
Achim. Mueller ◽  
Hartmut. Boegge
1993 ◽  
Vol 48 (11) ◽  
pp. 1613-1620 ◽  
Author(s):  
Helmut Fischer ◽  
Claudia Kalbas ◽  
Carsten Troll ◽  
Klaus H. Fluck

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.


1991 ◽  
Vol 46 (12) ◽  
pp. 1601-1608 ◽  
Author(s):  
Dieter Sellmann ◽  
Stefan Fünfgelder ◽  
Falk Knoch ◽  
Matthias Moll

In order to elucidate specific properties of nickel sulfur complexes, redox and addition-elimination reactions of [Ni(′OS4')]2, [Ni(′NHS4')]2, [Ni(′S5')], [Ni('S4—C5')], and [Ni('S4—C3')] were investigated ('OS4′ 2' = 2,2'-bis(2-mercaptophenylthio)diethylether(2—), 'NHS4'2- = 2,2'-bis(2-mercaptophenylthio)diethylamine(2—), 'S5'2- = 2,2'-bis(2-mercaptophenylthio)diethylsulfide(2—), 'S4-C5'2- = 1,5-bis(2-mercaptophenylthio)pentane(2—), 'S4—C3'2- = 1,3-bis(2-mercaptophenylthio)propane(2—)).Cyclovoltammetry proves the complexes to be redox inactive between —1.4 and +0.8 V vs. NHE. Above +0.8 V the complexes are irreversibly oxidized, below —1,4 V desalkylation takes place and [Ni(′S,′)2]2- is formed. An X-ray structure analysis was carried out of (NMe4)2[Ni(′S2')2], which shows a planar anion with the Ni center in a nearly perfect square planar coordination. Distances and angles are practically identical to those in the [Ni(′S2')2-] monoanion.The complexes coordinate only phosphines as coligands, but thioether donors simultaneously decoordinate and, dependant of reaction temperature, mono- or trisphosphine complexes are formed. [Ni(′S4—C3')(PMe3)] was characterized by X-ray structure analysis and exhibits a square pyramidal coordination geometry.


1982 ◽  
Vol 37 (10) ◽  
pp. 1284-1288 ◽  
Author(s):  
Ernst Otto Fischer ◽  
Jiabi Chen ◽  
Ulrich Schubert

Abstract Symmetrical anhydrides of hydroxycarbene complexes of manganese and rhenium, [π-C5H5(CO)2MC(R)]2O, (M = Mn, Re) are prepared by reaction of cationic carbyne complexes [π-C5H5(CO)2MCR]BX4 with the corresponding metal carbonyl acylates Li[π-C5H5(CO)2MC(O)R]. [π-C5H5(CO)2MnC(C6H5)]2O is also obtained by controlled hydrolysis of π-C5H5(CO)2MnCX(Br)Ce6H5. The new complexes are characterized spectroscopically and by an X-ray structure analysis of [π-C5H5(CO)2MnC(C6H5)2O.


1994 ◽  
Vol 49 (5) ◽  
pp. 660-664 ◽  
Author(s):  
Dieter Sellmann ◽  
Helge Friedrich ◽  
Falk Knoch

Attempts to coordinate N2H4 to [Fe(S2C6H4)2] fragments lead to N2H5[Fe(N2H4)(S2C6H4)2], which crystallizes from MeOH/N2H4 solutions as the solvate [(N2H5){Fe(N2H4)(S2C6H4)2} · 1,33 N2H4]. 1, and has been characterized by X-ray structure analysis. 1 contains three discrete N2H5+ cations, four N2H4 solvate molecules and three independent [Fe(N2H4)(S2C6H4)2]- anions which are connected via an extended network of N-H ··· N and N-H ··· S bridges. N2H5[Fe(N2H4)(S2ChH4)2] and 1 contain high-spin Fe(III) centers and labile N2H4 ligands.


1989 ◽  
Vol 8 (12) ◽  
pp. 2800-2804 ◽  
Author(s):  
Lothar. Weber ◽  
Dagmar. Bungardt ◽  
Achim. Mueller ◽  
Hartmut. Boegge

1989 ◽  
Vol 44 (8) ◽  
pp. 917-922 ◽  
Author(s):  
Wolf Peter Fehlhammer ◽  
Hans Hoffmeister ◽  
Borislav Boyadjiev ◽  
Thomas Kolrep

The X-ray structure analysis of (trans-4,5-dimethyloxazolidin-2-ylidene)triphenylboron reveals a stereochemistry of the carbene ligand which is almost identical with that in transition metal complexes. Deprotonation of triphenylboron stabilized oxazolidin-2-ylidenes with NaH leads to (oxazolin-2-ato)borates, which have been N-alkylated with [R3O+][BF4~] or RI under mild conditions.


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