Studies on poly(iminomethylenes)

A variety of simple alkyl and aryl isocyanides have been polymerized using 0.5% NiCl₂ in ethanol as a catalyst. The resulting poly(iminomethylenes) have been characterized by carbon-13 NMR spectroscopy and their polystyrene-equivalent molecular weights have been determined by gel permeation chromatography. Straight chain aliphatic isocyanides having from three to ten carbon atoms in the chain form readily solyble polymers having molecular weights (M_w) in the general range 10,000 to 30,000. Neopentyl isocyanide unlike tert-butyl isocyanide forms an insoluble polymer. A number of new soluble aryl isocyanide polymers have been obtained. However, aryl isocyanides having a single alkyl substituent (CH₃, C₂H₅, CF₃) in the ortho position give only insoluble polymers, whereas aryl isocyanides having alkyl substituents in both ortho positions (e.g., 2,6-(CH₃)₂C₆H₃NC and 2,4,6-(CH₃)₃C₆H₂NC) fail to polymerize under these conditions. The highest molecular weight soluble aryl isocyanide homopolymer is obtained from 3-CH₃OC₆H₄NC(M_w = 26,000). The trimethylsilyl substituted isocyanide (CH₃)₃SiCH₂CH₂NC has been obtained from LiCH₂NC and (CH₃)SiCH₂Cl and gives a brown soluble homopolymer with a molecular weight (M_w) of 19,000.     

Studies on vinyl isocyanides

The vinyl Isocyanides 2,4,6-(CH₃)₃C₆H₂CHCHNC and (CH₃)₃CCHCHNC and the new 1,3-dienyl isocyanide CH₃CHCH(CH₃)-CHCHNC have been prepared from the corresponding aldehydes and methyl isocyanide using a method first developed by Schöllkopf, Stafforst, and Jentsch. ⁵ The new vinyl isocyanides (CH₃)₂CCHNC and CH₃CHC(CH₃)NC have been prepared by the Cu₂O-catalyzed isomerization of the corresponding allyl isocyanides The liquid vinyl isocyanides may be characterized by the formation of solid cis-(RNC)₂Mo(CO)₄ derivatives through reaction with norbornadienetetracarbonylmolybdenum in hexane solution at ambient temperature. Examination of these molybdenum carbonyl complexes by proton and carbon-13 NMR spectroscopy Indicates that the isocyanide carbon atom but not the carbon-carbon double bond of the vinyl 1socyanide ligands is bonded to the molybdenum atom. The proton-decoupled carbon-13 NMR spectra of the vinyl isocyanides, but not their molybdenum carbonyl complexes, indicate coupling of the isocyanide nitrogen to both the isocyanide carbon (¹J(C-N)6 Hz. ) and the vinyl carbon bearing the isocyanide group (¹J(C-N)11-13 Hz. ) leading to 1:1:1 triplets for these resonances. These vinyl carbonyl resonances are used to estimate the cis-trans isomer ratios in vinyl isocyanides of the type RCHCHNC. Such studies suggest that the formation of vinyl isocyanides by the copper(I) catalyzed isomerization of the corresponding allylic isocyanides is more nearly stereospecific than the formation of vinyl isocyanides by the elimination reaction of the Schollkopf/Stafforst/Jentsch synthetic method.     

Photochemical reaction between cyclohexyl isocyanide and π-cyclopentadienyldicarbonyltrimethylsilyliron(II)

The photoreaction between C₅H₅Fe(CO)₂Si(CH₃)₃ (I) and cyclohexyl isocyanide leads to the sequential replacement of both carbonyl groups by the isocyanide. Both the racemic monosubstituted product, C₅H₅Fe(CO)(C₆H₁₁NC)Si(CH₃)₃ (II) and the disubstituted product, C₅H₅Fe(C₆H₁₁NC)₂Si(CH₃)₃ (III) have been isolated and characterized. Photoreaction between the disubstituted product III and C₅H₅Fe(CO)₂Si(CH₃)₃ in a sealed tube gives the monosubstituted product, II. Thermal initiation of the above reactions failed. The disubstituted product III is stable under both the thermal and photochemical conditions used; thus, insertion of isocyanide into FeSi bond was observed not to occur.     

The electron-impact-induced fragmentation of some alkyl isocyanides and α-branched alkyl cyanides

The HRP mass spectra of some alkyl isocyanides (R? NC in which R equals CH₃, C₂H₅, n-C₃H₇, n-C₄H₉ and t-C₄H₉) and two methyl branched alkyl cyanides (R? CN in which R equals i-C₃H₇ and t-C₄H₉) have been studied. Using metastable ion transitions and appearance potentials, the fragmentation patterns and spectral characteristics of the isocyanides can be given. A comparison has been made with the mass spectral data of the corresponding cyanides. Although the mass spectra of alkyl cyanides and isocyanides show close relationship, evidence could be obtained that this resemblance is not caused by rearrangement of the isocyanide into cyanide molecules. The main difference between the spectra of both compounds is caused by the strength of the α-bond, being weaker in the case of the isocyanides. The abundance of ions formed by α-bond cleavage decreases with increasing size of the alkyl group.     

Novel Copolymers of Styrene. 3. Oxy Ring-disubstituted 2-cyano-3-phenyl-2-propenamides

Novel electrophilic trisubstituted ethylene monomers, oxy ring-disubstituted 2-cyano-3-phenyl-2-propenamides, RC₆H₃CH? C(CN)CONH₂ (where R is 2,3-(CH₃O)₂, 2,4-(CH₃O)₂, 2,5-(CH₃O)₂, 2,6-(CH₃O)₂, 3,4-(CH₃O)₂, 3,5-(CH₃O)₂, 3-CH_3?4-CH₃O, 3-C₂H₅O-4-CH₃O, 3,4-(C₆H₅CH₂O)₂, 2-C₆H₅CH₂O-3-CH₃O, 3-C₆H₅CH₂O-4-CH₃O, 4-C₆H₅CH₂O-3-CH₃O) were synthesized by potassium hydroxide catalyzed Knoevenagel condensation of ring-disubstituted benzaldehydes and cyanoacetamide, and characterized by CHN analysis, IR, ¹H- and ¹³C-NMR. Novel copolymers of the ethylenes and styrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator, AIBN at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H- and ¹³C-NMR. High T_g of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 300–500°C range with residue (2–9% wt), which then decomposed in the 500–800°C range.     

Insertion reactions of isocyanides with platinumcarbon σ-bonded complexes

[Pt(C₁₀H₁₂OCH₃)(PPh₃)Cl] reacts readily with isocyanides by displacement of the coordinated olefinic end of the organic moiety followed by insertion of the isocyanide into the metalcarbon σ-bond. The reaction between the methoxydienyl complex [Pt(C₁₀H₁₂OCH₃)Cl]₂ and cyclohexyl isocyanide involves chloride bridge-splitting to give [Pt(C₁₀H₁₂OCH₃)(C₆H₁₁NC)Cl], followed by olefin displacement and finally isocyanide insertion. The imino derivative produced in this latter reaction has a trans-isocyanide configuration.The chemical properties of these new isocyanide complexes are discussed in terms of relative trans influences, coordinating abilities, and electrophilic characters in comparison with the CO analogues.     

Novel Copolymers of 4-Fluorostyrene. 10. Some Ring-substituted 2-Phenyl-1,1-dicyanoethylenes

Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC₆H₂CH=C(CN)₂ (where R is 4-C₆H₅O, 2-C₆H₅CH₂O, 3,4-(C₆H₅CH₂O)₂, 2-C₆H₅CH₂O-3-CH₃O, 3-C₆H₅CH₂O-4-CH₃O, 2-Cl-6-NO₂, 4-Cl-3-NO₂, 5-Cl-2-NO₂) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C-NMR. The order of relative reactivity (1/r ₁) for the monomers is 3,4-(C₆H₅CH₂O)₂(31.0) > 2-C₆H₅CH₂O-3-CH₃O (24.8) > 3-C₆H₅CH₂O-4-CH₃O (15.2) > 4-C₆H₅O (3.1) > 4-Cl-3-NO₂ (1.9) > 2-Cl-6-NO₂ (1.6) > 5-Cl-2-NO₂ (1.5) > 2-C₆H₅CH₂O (1.4). High T_g of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 270-400°C range with residue, which then decomposition in 400–800°C range.     

Reactions of nucleophiles with cyclopentadienyliron complexed halotoluenes

η⁶-o-Chlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate undergoes nucleophilic substitution of the chlorine atom with anions generated (K₂CO₃/DMF) from methyl thioglycolate, diethyl malonate, dimethyl malonate, methyl acetoacetate and 2,4-pentanedione. The compounds prepared were o-CH₃C₆H₄SCH₂CO₂CH₃FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂CH₃)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(COCH₃)CO₂CH₃FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH₂COCH₃FeCp⁺PF₆ . Similarly, the reaction of diethyl malonate, dimethyl malonate, methyl acetoacetate anions and methylamine with η⁶-2,6-dichlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate yielded monosubstitution of one of the chloro groups. The complexes prepared in this study were η⁶-diethyl(3-chloro-2-methyl) phenylmalonate- η⁵-cyclopentadienyliron hexafluorophosphate, η⁶-dimethyl(3-chloro-2-methyl)phenylmalonate-η⁵-cyclopentadienyliron hexafluorophosphate, η⁶-methyl(3-chloro-2-methyl)phenylacetoacetate-η⁵-cyclopentadienyliron hexafluorophosphate and η⁶-3-chloro(2-methyl-N-methyl)aniline-η⁵-cyclopentadienyliron hexafluorophosphate. Reaction of η⁶-2,6-dichlorotoluene-η⁵-cyclopentadienyliron hexafluorophosphate with excess methanol as well as methyl thioglycolate in the presence of K₂CO₃ resulted in disubstitution of both chloro groups to yield new complexes, η⁶-2,6-dimethoxytoluene-η⁵-cyclopentadienyliron hexafluorophosphate and η⁶-methyl[(2-methylphenyl)1,3-dithio] diacetate-η⁵5-cyclopentadienyliron hexafluorophosphate, respectively. Complexes o-CH₃C₆H₄CH(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄CH(CO₂CH₃)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH₂ COCH₃FeCp⁺ PF₆⁻ react with excess K₂CO₃ and benzyl bromide in refluxing methylene chloride to give 80–90% yields of complexes o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂CH₃)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄CH(CH₂C₆H₅)COCH₃FeCp⁺PF₆⁻, respectively. Reaction of complex, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ with one molar equivalent of t-BuOK followed by acidic work-up gives o-(C₂H₅CO₂CH₂)C₆H₄CH(CO₂C₂H₅)CH₂C₆H₅FeCp⁺PF₆⁻. Similarly, reactions of complexes o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ and o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂CH₃)₂FeCp⁺PF₆⁻ with t-BuOK in THF followed by alkylation with methyl iodide gave the new complexes, o-(C₂H₅O₂C(CH₃)CH)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅FeCp⁺PF₆⁻ and o-(CH₃O₂C(CH₃)CH)C₆H₄CH(CH₂C₆H₅)CO₂CH₃FeCp⁺PF₆⁻, respectively. Vacuum sublimation of the new complexes, o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂FeCp⁺PF₆⁻ and o-(C₂H₅O₂CCH₂)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅FeCp⁺PF₆⁻ gives o-CH₃C₆H₄C(CH₂C₆H₅)(CO₂C₂H₅)₂ and O-(C₂H₅O₂CCH₂)C₆H₄CH(CH₂C₆H₅)CO₂C₂H₅, respectively.     

Diazabutadienes as ligands: I. Compounds of aluminium: coordination of diazabutadienes to Al(CH3)3 and subsequent intramolecular insertion and rearrangement reactions leading to (CH3)2AIR—N—CH(CH3)—C(R')=N—R(R'= H,CH3) and (CH3)2AIR—N—CH2—C(CH3)=N—R

Reaction of R—N=CH—CH=N—R with [(CH₃)₃Al]₂ affords the coordination product (CH₃)₃AlRN=CH—CH=NR (A) for R = 2,6-(CH₃)₂C₆H₃ and 2,4,6(CH₃)₃C₆H₂. For R = 4 ClC₆H₄, 4-CH₃C₆H₄ and 4-CH₃OC₆H₄, insertion takes place, giving the complexes (CH₃)₂A$\text{lRN—CH(CH}{}_3\text{)—CH=N}$—R (B), in which Al is part of a five-membered chelate ring. Depending on the temperature both the addition and insertion products rearrange intramolecularly to the complexes (CH₃)₂-A$\text{lR—N—CH}{}_2\text{—C(CH}{}_3\text{)=N}$—R (C), in which Al is also part of a five-membered chelate ring. Reactions of the asymmetric (CH₃)₂HC—N=CH—C(CH₃)=N—CH-(CH₃)₂ with [Al(CH₃)₃]₂ also leads to an insertion product, (CH₃)₂A$\text{lRN-—CH(CH}{}_3\text{)—C(CH}{}_3\text{)=N}$—R (B') (R = (CH₃)₂CH), but there is no subsequent rearrangement in this case.A mechanism involving hydrogen migration is tentatively proposed to account for the observed isomerization, which increases in rate in the order:R = (CH₃)₃C>2,4,6-(CH₃)₃C₆H₂> 2,6-(CH₃)2C₆H₃ (A → C)andR = 4-CH₃OC₆H₄>4-CH₃C₆H₄>4-ClC₆H₄ (B → C)Hydrolysis of isomer C gives the unknown imino amines R—NH—CH₂-C(CH₃)=N—R in quantitative yield.     

Regioselective anion generation and alkylation at carbon α to nitrogen in (CO)5WC[N(CH3)2]C6H4-p-CH3

Treatment of (CO)₅WC[N(CH₃)₂]C₆H₄-p-CH₃ (1) with lithium diisopropylamide (LDA) in THF at −78°C followed by quenching with D₂O leads to incorporation of deuterium into the (E)-N-methyl group only. Reaction of the anion of 1 with benzyl bromide at −78°C followed by quenching with water gave the E-isomer of (CO)₅WC[N(CH₃)CH₂CH₂C₆H₅]C₆H₄-p-CH₃ (2E, 26%) and recovered 1. When a mixture of the anion of 1 and benzyl bromide was warmed from −78°C to ambient temperature, a mixture of the E-isomer of the dibenzylated product (CO)₅WC[N(CH₃)CH(CH₂C₆H₅)₂]C₆H₄-p-CH was obtained. Reaction of the anion of 1 with allyl bromide gave (CO)₅WC[N(CH₃)CH₂CH₂CHCH₂]C₆H₄-p-CH₃ (5, 38%) and with methyl iodide gave a mixture of (CO)₅WC[N(CH₃)CH₂CH₃]C₆H₄-p-CH₃ (6, 7%) and (CO)₅W C[N(CH₃)CH(CH₃)₂]C₆H₄-p-CH₃ (7, 16%).     

Ringöffnende acetylierung eines an kobalt koordinierten ringliganden vom divinylboran-typ

(C₅H₅)Co[2–6-η-(CH₃)₂Si(CHCH)₂BC₆H₅(III) is prepared photochemically from (C₅H₅)Co(CO)₂ and (CH₃)₂Si(CHCH)₂BC₆H₅ (II). Acetylation of the new complex III with CH₃COCl/AlCl₃ and subsequent hydrolysis effect ring-opening new complex III with CH₃COCl/AlCl₃ and subsequent hydrolysis effect ring-opening to give (C₅H₅)Co[(1,2-η-(cis-CH₃COCH)CH(η-CH₂CH)Si(CH₃)₂] (IV) which slowly isomerizes (ΔG^≠₂₉₆ 100 ± 2 kJ mol^?1) to the corresponding trans-isomer (V).Pure (CH₃)₂Si(CHCH)₂Sn(CH₃)₂ (I) can be obtained in preparative quantities via the new complex (CH₃)₂Si(CHCH)₂Sn(CH₃)₂ · 2 CuCl.     

The isocyanide-induced formation of dicyclopentadienyltantalummonoalkyl species from hydride olefin complexes

Reaction of endo Cp₂Ta(H)L (L = C₃H₆, C₄H₈ (1-butene)) with aryl- and alkyl-isocyanides R′NC (R′ = 2,6-(CH₃₂C₆H₃, cyclo-C₆H₁₁, CH₃ and t-C₄H₉) gives the thermally stable isocynaide adducts of Cp₂TaR (R = C₃H₇, C₄H₉). The extraordinarily strong metalisocyanide interaction leads to a non-linear “carbene-like” structure for these complexes and gives rise to the possibility of reactions at the nitrogen lone-pair electrons. The tantalocene isocyanide complexes react with Lewis acids, such as AlEt₃ to give 1/1 adducts Cp₂Tar · R′NC : AlEt₃.     

The electronic properties of isocyanides at rhenium—dinitrogen binding sites. Preparation and redox properties of the isocyanide complexes trans-[ReCl(CNR)(Ph2PCH2CH2PPh2)2]

The isocyanide complexes trans-[ReCl(CNR)(dppe)₂] (R  Me, Bu^t, C₆H₄CH₃-4, C₆H₄CH₃-2, C₆H₄Cl-4, C₆H₄OCH₃-4 and C₆H₃Cl₂-2,6; dppe  Ph₂PCH₂CH₂PPh₂) have been prepared by isocyanide displacement of dinitrogen from the parent complex trans-[ReCl(N₂)(ddpe)₂]. Their redox properties have been studied by cyclic voltammetry and are interpreted on the basis of the electronic properties and the geometry of the ligating isocyanides which are believed to be bent in these complexes, appearing to exhibit ligand parameter (P_L) values ca. +0.3 V higher than those which would be expected for linear geometry. A very high polarisability (B ? 3.4) is observed for the {ReCl(dppe)₂} site.     

Novel Copolymers of Vinyl Acetate and Some Ring‐Substituted 2‐Phenyl‐1,1‐dicyanoethylenes

Electrophilic trisubstituted ethylene monomers, some ring‐substituted 2‐phenyl‐1,1‐dicyanoethylenes, RC₆H₄CH?C(CN)₂ (where R is 3‐C₆H₅O, 4‐C₆H₅O, 3‐C₆H₅CH₂O, 4‐C₆H₅CH₂O, 4‐CH₃CO₂, 4‐CH₃CONH, 4‐(C₂H₅)₂N) were synthesized by piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and malononitrile, and characterized by CHN elemental analysis, IR, ¹H‐ and ¹³C‐NMR. Novel copolymers of the ethylenes and vinyl acetate were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, ¹H and ¹³C‐NMR, GPC, DSC, and TGA. High T _g of the copolymers, in comparison with that of polyvinyl acetate, indicates a substantial decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the copolymers decompose in the 190–700°C range.     

Novel Copolymers of Styrene. 3. Some Ring-Substituted Butyl 2-Cyano-3-Phenyl-2-Propenoates

Novel trisubstituted ethylenes, ring-substituted butyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO₂C₄H₉ (where R is 2-C₆H₅CH₂O, 3-C₆H₅CH₂O, 4-C₆H₅CH₂O, 4-CH₃COO, 3-CH₃CO, 4-CH₃CO, 4-CH₃CONH, 2-CN, 3-CN, 4-CN, 4-(CH₃)₂N, 4-(C₂H₅)₂N) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and butyl cyanoacetate, and characterized by CHN analysis, IR, ¹H and ¹³C-NMR. All the ethylenes were copolymerized with styrene (M₁) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, ¹H and ¹³C-NMR. The order of relative reactivity (1/r₁) for the monomers is 4-C₆H₅CH₂O (6.39) > 2-C₆H₅CH₂O (2.06) > 3-CH₃CO (1.86) > 3-C₆H₅CH₂O (1.78) > 4-CH₃COO (1.58) > 3-CN (1.47) > 4-CN (1.21) > 4-(C₂H₅)₂N (1.19) > 4-(CH₃)₂N (1.18) > 2-CN (1.04) > 4-CH₃CO (0.71) > 4-CH₃CONH (0.63). Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (3.6–9.5% wt), which then decomposed in the 500–800°C range.     

The reaction of RTiBr3 (R = methyl,phenyl and p-tolyl) with some monodentate and bidentate ligands

RTiBr₃ (R = CH₃, C₆H₅ and (4-CH₃)C₆H₄) forms 1/2 adducts, RTiBr₃2L, with a number of monodentate ligands containing nitrogen, oxygen ad sulphur donor atoms. Bidentate ligands normally give 1/1 adducts, as do the bulky monodentate ligands (C₆H₅)₃PO. Dioxan gives 1/1 adducts with CH₃TiBr₃ and C₆H₅TiBr₅ but a 1/2 adduct with (4-CH₃)C₆H₄TiBr₃.Structures are assigned on the basis of IR and NMR data.     

Novel copolymers of styrene. 3. Some ring-substituted propyl 2-cyano-3-phenyl-2-propenoates

Novel trisubstituted ethylenes, ring-substituted propyl 2-cyano-3-phenyl-2-propenoates, RPhCH?C(CN)CO₂C₃H₇ (where R is 2-C₆H₅CH₂O, 3-C₆H₅CH₂O, 4-C₆H₅CH₂O, 4-CH₃COO, 3-CH₃CO, 4-CH₃CONH, 2-CN, 3-CN, 4-CN, 4-(CH₃)₂N, 4-(C₂H₅)₂N) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and propyl cyanoacetate, and characterized by CHN analysis, IR, ¹H and ¹³C-NMR. All the ethylenes were copolymerized with styrene (M₁) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, ¹H and ¹³C-NMR. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500°C range with residue (2.7–8.6% wt.), which then decomposed in the 500–800°C range.     

Alkaline hydrolysis of diaryl ditellurides under phase transfer conditions; synthesis of alkyl aryl tellurides

The disproportionation reaction of diaryl ditellurides [(C₆H₅Te)₂, (p-CH₃C₆H₄Te)₂, (p-CH₃OC₆H₄Te)₂, (p-C₂H₅OC₄Te)₂, (2-naphthyl-Te)₂] with sodium hydroxide under phase transfer conditions at room temperature is described for the first time. The phase transfer catalyst used is 2HT-75, a trade name for a mixture of dialkyldimethylammonium chlorides. The intermediates aryl tellurolates react “in situ” with alkyl halides to give the corresponding alkyl aryl tellurides (ArTeR) in 52–72% yield. The following compounds were prepared: Ar  C₆H₅, R=CH₃(CH₂)₃CH₂, (CH₃)₂CHCH₂CH₂, (CH₃)₂CHCH₂, CH₃CHBrCH₂CH₂, CH₃(CH₂)₈CH₂, C₆H₅CH₂, ClCH₂, C₆H₅CH₂CH₂, CH₂CHCH₂, C₆H₅CHCHCH₂, C₆H₅SeCH₂, $\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2\text{CHCHC}$H; Ar=p-CH₃C₆H₄, R = CH₃(CH₂)₂CH₂; Ar=p-CH₃OC₆H₄, R = CH₃(CH₂)₂CH₂; Ar = p-CH₂H₅OC₆H₄, R= CH₃(CH₂)₂CH₂; Ar = 2-naphthyl, R = CH₃(CH42)₂CH₂.     

Synthesis and reactivity of some isocyanide complexes of iridium(I)

Several isocyanide complexes [Ir(RNC)₄]X (I) (R = p-CH₃C₆H₄, X = I; R = p-CH₃OC₆H₄, X = I and PF₆) and [Ir(RNC)₂(PPh₃)₃] ClO₄(II) (R = p-CH₃C₆H₄ and p-CH₃OC₆H₄) have been prepared by the reactions of [Ir(COD)Cl]₂ and [Ir(COD)(PPh₃)₂]ClO₄ (COD = l,5-cyclooctadiene) with aryIisocyanides, respectively. Oxidative addition reactions of I and II with halogens, and II with π-acids such as tetracyanoethylene(TCNE), fumaronitrile, maleic anhydride, dimethyl fumarate, acrylonitrile, and dimethyl acetylenedicarboxylate are described. The structures of I, II and the π-acid addition products of II, [Ir(p-CH₃C₆H₄NC)₂ (PPh₃)₂ (π-acid)]ClO₄ (IV) (π-acid = TCNE, fumaronitrile, maleic anhydride, and acetylene dicarboxylate), are discussed on the basis of their electronic, IR, and NMR spectra. Especially, I is suggested to have an unusual layer structure involving Ir to Ir interaction, the result of which is relatively low reactivity in oxidative addition reactions. Trigonal bipyramidal configurations are suggested for IV with the two isocyanides in the trans and cis positions for the olefin and acetylene adducts, respectively.     

Reaktionsverhalten des Diäthylamino-divinylphosphines

Behaviour of Diethylamino-divinylphosphine The preparation of diethylamino-divinylphosphine 1 and its reaction with S_x, Br₂, CH₃J, HCl, HP(C₆H₅)₂, and HSn(C₄H₉)₃ are described. Whereas 1 and (C₆H₅)₂P? CH?CH₂ do'nt polymerize by a radical mechanism, (C₂H₅)₂N? P(S)(CH?CH₂)₂ yields an unburnable polymerisation product. Copolymerisation of (C₆H₅)₂P? CH?CH₂ or 1 , respectively, and styrene results in a polymeric substance with a molecular weight of about 2600.