Fluoraustauschreaktionen an Metalltrifluorphosphan-Komplexen. X [1]. Zum Reaktionsverhalten von Tetrakis(trifluorphosphan)-nickel(0) mit Metallorganylen [2]

Ni(PF₃)₄ ( 1 ) tauscht mit Lithiumorganylen und Grignard-Reagentien Fluor gegen Organyl-Gruppen aus, wobei die Komplexe ( 10–32 ) Ni(PF₃)_4?n(PF₂R)_n (n = 1, 2 und 3), Ni(PF₃)₃(PFR₂), Ni(PF₃)₂(PF₂R)(PFR₂) und Ni(PF₃)₃(PR₃) (R = organ. Rest) gebildet werden. Für den Reaktionsablauf wird ein Vierzentren-Synchron-Mechanismus vorgeschlagen. Fluorine Exchange in Trifluorophosphane Metal Complexes. X. Reactions of Tetrakis(trifluorophosphane)nickel(0) with Metal Organyls The fluorine atoms in Ni(PF₃)₄ ( 1 ) can be partially substituted by organyl groups yielding the complexes ( 10–32 ) Ni(PF₃)_4?n(PF₂R)_n (n = 1, 2 and 3), Ni(PF₃)₃(PFR₂), Ni(PF₃)₂(PF₂R)(PFR₂) and Ni(PF₃)₃(PR₃) (R = organyl group). The mechanism of these peripheric reactions is discussed by assuming a four centered type intermediate.     

Über Cyanatverbindungen und deren reaktives Verhalten. IX. Reaktionsverhalten von Vanadin(III)-thiocyanat gegenüber Pyridin-N-oxiden

V(NCS)₃ or V(NCS)₃(THF)₃ reacts under various conditions with pyridine-N-oxide to oxovanadium(IV)-complexes of the type VO(NCS)₂ · 4C₅H₅NO and VO(NCS)₂ · 5C₅H₅NO. Reactions with 4-picoline-N-oxide lead to VO(NCS)₂(4-CH₃C₅H₄NO₂)₂. The prepared compounds are characterised by analytical data, their spectral and magnetic properties, and IR absorption spectra. The mechanism of the reaction is discussed.     

Das unterschiedliche Reaktionsverhalten von basefreiem Tris(trimethylsilyl)methyl‐Lithium gegenüber den Trihalogeniden der Erdmetalle und des Eisens

The Variable Reaction Behaviour of Base‐free Tris(trimethylsilyl)methyl Lithium with Trihalogenides of Earth‐Metals and Iron Base‐free tris(trimethylsilyl)methyl Lithium, Tsi–Li, reacts with the earth‐metal trihalogenides (MHal₃ with M = Al, Ga, In and Hal = Cl, Br, I) primarily to give the metallates [Tsi–MHal₃]Li. Simultaneous to this simple metathesis a methylation also takes place, mainly with heavier halogenides of Ga and In with excess Tsi–Li, forming the mono and dimethyl compounds Tsi–M(Me)Hal (M = Ga, In; Hal = I), Tsi–MMe₂ (M = Ga), and the bis(trisyl)derivative (Tsi)₂InMe, respectively and the main by‐product 1,3‐disilacyclobutane. Representatives of each type of compound have been isolated by fractionating crystallizations or sublimations and characterized by spectroscopic methods (¹H, ¹³C, ²⁹Si NMR, IR, Raman) and X‐ray elucidations. Reduction takes place, when FeCl₃ reacts with Tsi–Li (1 : 3 ratio) in toluene at 55–60 °C, yielding red‐violet Fe(Tsi)₂, 1,1,1‐tris(trimethylsilyl)‐2‐phenyl ethane and low amounts of Tsi–Cl. Fe(Tsi)₂ is monomeric, crystallizes in the monoclinic space group C2/c and consists of a linear C–Fe–C skeleton with d(Fe–C) of 204,5(4) pm.     

Über Cyanatverbindungen und deren reaktives Verhalten. XXI. Reaktionsverhalten von Niob(V)- und Tantal(V)-thiocyanat gegenüber N-Donatoren

Cyanate Compounds and their Reactivity. XXI. Reactivity of Niobium(V) and Tantalum(V) Thiocyanates to N-Donators M₂(NCS)₁₀ reacts with ammonia or primary and secondary aliphatic amines to complexes of the types [M(NCS)(NH₂)₂NH]_x, [M(NCS)₃(NHR)₂ H₂NR], or [M(NCS)₃(NR′₂)₂ HNR′₂], with N-heterocyclic amines in a first step to [M(NCS)₅L]-complexes and in a further step through a redox mechanism to [M(NCS)₄L₂] complexes. [M(NCS)₅(CH₃CN)] mCH₃CN reacts with ammonia, or primary amines in acetonitrile over acetamidine and amidinolytic cleavage of M-NCS bonds to complexes of the type [M(NCS)_a(NC(NHR″)CH₃)_b(CH₃C(NH)NHR″)]_x. The prepared compounds are characterized by analytical data, derivatographic measurements, and IR or visible absorption spectra (M = Nb, Ta; x = 2; R = n-C₄H₉; R′ = C₂H₅; L = pyridine or 4-methyl-pyridine; m = 0, 1, 2; a = 1 or 4; b = 4 or 1; R″ = H, n-C₄H₉).     

Zum Reaktionsverhalten chlorsubstituierter Methanphosphonsäuredialkylester gegenüber Trialkylphosphiten,Dialkylphosphiten und Alkohol/Natriumalkoholat

On the Reaction of Chloro-substituted Methane Phosphonic Acid Dialkylester with Dialkylphosphites, Trialkylphosphites, or Alcohol/Sodium Alcoholate Dialkylesters of trichloromethane phosphonic acid react analogous to carbon tetrachloride with dialkylphosphites and alcohol in the presence of tertiary amines or with trialkylphosphites and alcohol yielding diesters of dichlormethane phosphonic acids and triesters of phosphoric acid. When esters of trichlormethane or dichloromethane phosphonic acid react with alcohols in the presence of sodium alcoholates a quantitative cleavage of P? C bond occurs and triesters of phosphoric acid and CHCl₃ or CH₂Cl₂ are formed.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. XXXV. Zum Reaktionsverhalten von Tetrabenzyltitan gegenüber Lithiumalkylen

Contributions to the Chemistry of Transition Metal Alkyl Compounds. XXXV. Reactions in Tetrabenzyl Titanium/Alkyllithium Systems Organotitanium(IV) complexes of the type Li[(C₆H₅CH₂)₄TiR] (R = CH₃, C₂H₅, n-C₄H₉) were isolated from tetrabenzyl titanium and lithium alkyls at deep temperature. The reddish brown, crystalline compounds decompose between ?30 and 0°C with formation of benzyltitanates(II) which composition differs between Li₂[Ti(CH₂C₆H₅)₄] and Li[Ti(CH₂C₆H₅)₃]. From these complexes pure dibenzyl titanium can be isolated. The reaction mechanism is discussed. Experiments for isolation of a benzyl titanium(III) compound from (C₆H₅CH₂)₄Ti/RLi systems failed in all cases. Recent informations about stable tribenzyl titanium obtained from tetrabenzyl titanium and ethyl lithium could not be confirmed.     

Reaktivität von Monophosphan-Platin(0)-Verbindungen gegenüber Schwefeldioxid

Reactivity of Monophosphine Platinum(0) Complexes with SO₂ . The addition reaction of (PPh₃)Pt(ViSi) (ViSi = {η²-H₂C?CHSiMe₂}₂O) ( 1 ) with SO₂ gives within 30 min the red SO₂ complex (PPh₃)Pt(η²-H₂C?CHSiMe₂- OSiMe₂CH?CH₂)(SO₂) ( 2 ). A reaction time of 24 h with SO₂ leads to the elimination of the ViSi ligand, and the unstable monomeric intermediate (PPh₃)Pt(SO₂) cyclo- trimerizes to the stable cluster [Pt(PPh₃)(SO₂)]₃ ( 3 ). 3 is also obtained within 30 min by the reaction of (PPh₃)Pt(C₂H₄)₂ ( 4 ) with SO₂. The crystal structure of 3 has been determined; space group P2₁/n, Z = 4, a = 1 606.1(3), b = 1 019.3(1), c = 3 624.6(5) pm, β = 93.67°, R/R_w = 0.102/0.121.     

Bildung und Eigenschaften von Acylphosphanen. IX. Reaktion von Phenylbis(trimethylsilyl)phosphan mit Formaldehyd und Dimethylformamid

Syntheses and Properties of Acylphosphanes. IX. Reaction of Phenylbis(trimethylsilyl)-phosphane with Formaldehyde and Dimethylformamide Trimethylsilylphosphanes add to carbonyl compounds. Therefore phenyl-bis(tri-methylsiloxymethyl)phosphane 3 can be prepared by reacting phenylbis(trimethylsilyl)phosphane 1 with formaldehyde 2 . With dimethylformamide 4 , however, an addition-elimination-reaction yields hexamethyldisiloxane 6 and N,N-dimethylaminomethyliden-phenylphosphane 5 . NMR-spectroscopic studies show the rotation of the dimethylamino group to be hindered. The dimer 2,4-bis(N,N-dimethylamino)-l,3-diphenyl-l,3-diphosphetane 11 is isolated as a by-product.     

Bildung und Eigenschaften von Acylphosphanen. VI. Synthese von Alkyl- und Arylbis (trimethylsilyl)- sowie Alkyl und Aryltrimethylsilyphosphanen

Syntheses and properties of Acylphyosphanes. VI. Syntheses of Alkyl- or Arylbis (trimethylsilyl)- and Alkyl- or Aryltrimethylisilyphosphanes Methods for the preparation of alkyl-or arylbis (trimethylsily)-and alkyl-or aryltrimethylsilyphosphanes are described.

• 1 Primary phosphanes used for the syntheses of the title compounds were prepared by known methods (reduction with LiAlH₄).
• 2 Alkyl- and arylbis(trimethylsily) phosphanes are obtained from the corresponding dilithium phosphides (primary phosphanes and methyllithium) and trimethylchlorosilane or from lithiumbis (trimethylsilyl) phosphide and alkyl halides.
• 3 Suitable syntheses for alkyl-or aryltrimethylsilylphosphanes are the reactions of alkyl-and aryllithiumphosphides with trimethylchlorosilane or of alkyl- and arylbis (trimethylsily) phosphanes with methanole. The reaction between phenylbis (trimethylsilyl)phosphane and water was studied in detail and the formation of trimethylsilanole was proved by ¹H-n.m.r. spectroscopy.

The reactions of lithiumtrimethylsilyphosphides and 2,2-dimethylpropionyl chloride yield (2,2- dimethylpropionyl) trimethylsilylphosphanes (keto forms).     

Metallkomplexe mit anionischen Liganden von Elementen der 4. Hauptgruppe. IX. Zum komplexchemischen Verhalten von Trichlorstannid-und Trichlorgermid-Ionen gegenüber Komplexen von Übergangsmetallen in niedrigen Oxydationsstufen

Metal Complexes with Anionic Ligands of the Main Group IV Elements. IX. Reactions of Trichlorostannide and Trichlorogermide Ions with Complexes of Transition Metals in Low Oxidation States Carhonyl trichlorostannido- and carbonyl trichlorogermido-metalate complexes have been synthesized both by photochemical and thermical substitution reactions of [ECl₃]^? ions (E = Sn, Ge) with M(CO)₆, (M = Cr, Mo, W), Fe(CO)₅ Fe₃(CO)₁₂, Co₂(CO)₈, as well as with the metalcarbonyl derivatives (π-arene)M(CO)₃, (M = Cr, Mo), (h⁵-C₅,H₅,)V(CO)₄, Mn(CO)₅,Cl, Co(NO)(CO)₃, and Fe(NO)₂,(CO)₂. Mainly the bonding properties of the [ECl₃]^? ligands are discussed by means of i.r. spectroscopic investigations. The progress of the reactions and the necessary reaction conditions show that the nucleophilic properties oft both anions [ECl₃]^? are unexpectedly small. The slightly weaker hasicity of [SnCl₃]^? compared with [GeC1₃]^? arreared, when both anions were reacted with Co₂,(CO)₈, forming the substitution product. [Co₂,(CO)₇,SnCl₃]^? and the products of a “base reaction” Cl₃GcCo(CO)₄, and [Co(CO)₄]^?.     

Zum Reaktionsverhalten des polycyclischen Oligoalumosiloxans [Ph2SiO]8[AlO(OH)]4 gegenüber Hexamethyldisilazan

The Reaction Behaviour of the Polycylic Oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ towards Hexamethyldisilazane The reaction of the oligoalumosiloxane [Ph₂SiO]₈[AlO(OH)]₄ ( 1 ) with hexamethyldisilazane leads to the triple ionic [Ph₂SiO]₈[AlO₂]₂[AlO(O‐SiMe₃)]₂[NH₄·THF]₂·2 THF ( 2 ) and in the presence of pyridine to [Ph₂SiO]₈[AlO_1.5]₄·2py·1.5 C₇H₈ ( 3 ). Apart from the usual characterization techniques (NMR and IR spectroscopy) the molecular structures of 2 and 3 have been determined by single‐X‐ray diffraction analyses. Both alumosiloxanes 2 and 3 present new types of molecular structures with a central four membered Al₂O₂‐ring, on which the further aluminium atoms are attached via oxygen atoms. This leads to an Al₄‐lozenge, which is centered in subtriangles by oxygen atoms.     

Zum komplexchemischen Verhalten von potentiell vier- und fünfzähligen Bis(salicylidenamino)-Liganden gegenüber Ionen der 3d-Elemente

Studies on the Coordinative Behaviour of Potentially Four and Fivedentate Bis(salicylidene amino)-Ligands with Ions of the 3d-Elements. Fourdentate bis(salicylidene amino)-ligands (^?ONΦCH₂ΦNO^? and ^?ONΦOΦNO^?, meaning of the abbreviations see text) with the centres of donor atoms connected by rigid, bifunctional residues, form polymeric complexes Me^II(ONΦCH₂ΦNO) and Me^II(ONΦOΦNO) with cobalt(II), nickel(II), and copper(II). Among the cobalt(II) chelates the structure is uniformly tetrahedral, but the nickel(II) and copper(II) complexes contain square planar central atoms and such with a higher coordination number side by side. The potential fivedentate ligands ^～ON3PPh3NO^?, ^?ON2O2NO^?, and ^?ON2S2NO^? differ as to their coordinative behaviour. The coordination number of the complexes Ni(ON3PPh3NO) and Co(ON3PPh3NO) is five. On the other hand the compounds Co(ON2S2NO) and Co(ON2O2NO) are tetrahedral. No coordination of the ether or sulfide group is observed. Ni(ON2O2NO) has an octahedral structure which is produced by coordination polymerisation and possibly by coordination of the ether group. The new complexes are compared with the transition metal complexes of simple salicylaldimines.