Cyano polymers

Due to the nucleophilicity of both carbon and nitrogen atoms in cyanides, numerous polymers with (M-CN M-) and (M-SCN- M) linkages are found. Examples include AgCN, 43, and AgSCN, 44, which exhibit low conductivities (— 10 i fi- cm ) (46). One-dimensional cyano polymers with metals indifferent oxidation states have not been reported. Due to valence interchange these materials should exhibit a higher conductivity. 

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The cyanyopolysiloxane chiral stationary phases can be used in two ways. The polymer can include the chiral agent, usually a peptide or dipeptide and thus provide an overall polar interaction with the solutes, which would be more suitable for the separation of polar solutes. The temperature stability of the cyano polymer phases is, however, less than that of the phenyl polymer phases and can only be used up to temperatures (conservatively) of about 160°C. 

Synonyms Cetramin Dicyandiamide-formaldehyde adduct Dicyandiamide-formaldehyde polymer Guanidine, cyano-, polymer with formaldehyde Formula (C2H4N4 CH20)x Toxicology LD50 (oral, rat) 1750 mg/kg mod. toxic by ing. irritating to eyes and skin Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of NOx and CN ... 

The iron cyano polymer [PcFeCN] [35b] shows a conductivity comparable to that of the cobalt polymer. Lower values for the (M-cyano)phthalocyaninatomanganese and chromium compounds [ 35c,d ] (Table 4) in the range of 10 - 10 S cm were... 

An unusual method for the preparation of syndiotactic polybutadiene was reported by The Goodyear Tire Rubber Co. (43) a preformed cobalt-type catalyst prepared under anhydrous conditions was found to polymerize 1,3-butadiene in an emulsion-type recipe to give syndiotactic polybutadienes of various melting points (120—190°C). These polymers were characterized by infrared spectroscopy and nuclear magnetic resonance (44—46). Both the Ube Industries catalyst mentioned previously and the Goodyear catalyst were further modified to control the molecular weight and melting point of syndio-polybutadiene by the addition of various modifiers such as alcohols, nitriles, aldehydes, ketones, ethers, and cyano compounds. 

Oxetane, 2-(o -chlorobenzyl)-2-phenyl-X-ray crystal structure, 7, 366 Oxetane, 3-chloromethyl-3-ethyl-ring strain, 7, 370-371 Oxetane, 2-(o-chlorophenyl)- H NMR, 7, 367 Oxetane, 2-cyano-synthesis, 7, 391-392 Oxetane, 2-cyano-3,3-dimethyl-2-phenyl-thermolysis, 7, 372 Oxetane, 2,2-dialkoxy-synthesis, 7, 396 Oxetane, 2,2-dialkyl-isomerization, 7, 377 Oxetane, 3,3-dialkyl-alkylative cleavage, 7, 381 polymers, 7, 382 Oxetane, 2-diethylamino-synthesis, 7, 390 Oxetane, 3,3-difluoro-molecular dimensions, 7, 365 Oxetane, 2,2-dimethyl-mass spectra, 7, 368-369 photolysis, 7, 373 synthesis, 7, 393 Oxetane, 2,3-dimethyl- H NMR, 7, 366 thermolysis, 7, 372 Oxetane, 2,4-dimethyl-mass spectrum, 7, 369... 

Generation of radicals by redox reactions has also been applied for synthesizing block copolymers. As was mentioned in Section II. D. (see Scheme 23), Ce(IV) is able to form radical sites in hydroxyl-terminated compounds. Thus, Erim et al. [116] produced a hydroxyl-terminated poly(acrylamid) by thermal polymerization using 4,4-azobis(4-cyano pentanol). The polymer formed was in a second step treated with ceric (IV) ammonium nitrate, hence generating oxygen centered radicals capable of starting a second free radical polymeriza-... 

It would be preferable to incorporate both fluorescent and electron transport properties in the same material so as to dispense entirely with the need for electron-transport layers in LEDs. Raising the affinity of the polymer facilitates the use of metal electrodes other than calcium, thus avoiding the need to encapsulate the cathode. It has been shown computationally [76] that the presence of a cyano substituent on the aromatic ring or on the vinylene portion of PPV lowers both the HOMO and LUMO of the material. The barrier for electron injection in the material is lowered considerably as a result. However, the Wessling route is incompatible with strongly electron-withdrawing substituents, and an alternative synthetic route to this class of materials must be employed. The Knoevenagel condensation... 

Figure 9-1. Materials overview a few sclcclcd conjugated polymers and Ihcir properties have been compiled and ihe following abbreviations arc used DO-PPP...Poly(2-decyloxy-l,4-phcnylcnc), EHO-PPP...Poly(2-(2 -elhylliexyloxy)-l,4-phcnylenc), CN-PPP... Poly(2-(6 -cyano-6 -incthyl-licplyloxy)-l,4-phcnylene), m-LPPP... methyl-substituted ladder-type Poly( 1,4-phenylcne), and PLQY=phololuinincs-ecncc quanluni yield.

Starting from the assumption that the geometry relaxation after excitation is of primary importance with respect to the luminescence response, we decided to employ a solid polymer matrix to suppress conformational changes of the oligomers. For the measurements, dilute blends with polysulfone as the transparent host matrix were prepared. In Figure 16-13, the PL decay curves for the two cyano compounds in both chloroform and polysulfone are presented, as are the PL spectra of Ooct-OPV5-CN in chloroform and polysulfone [69J. 

The optical properties can be tuned by variations of the chromophores (e.g. type of side-chains or length of chromophorc). The alkyl- and alkoxy-substituted polymers emit in the bluc-gnecn range of the visible spectrum with high photolu-inincsccncc quantum yields (0.4-0.8 in solution), while yellow or red emission is obtained by a further modification of the chemical structure of the chromophores. For example, cyano substitution on the vinylene moiety yields an orange emitter. 

Two polymers have been prepared with the benzophenone tetracarboxylic dianhydride (BTDA) and either bis-l,3-(4-aminophenoxy)-benzene or bis-l,3-(4-aminophenoxy)-2-cyano-benzene (Fig. 5.6). Both polymers are soluble in NMP and their Tg values are respectively 191 and 243°C.59... 

By coelectrolysis of polymethacrylic acid with e-acetaminocaproic acid or cyano-acetic acid the alkylacetamido- or cyanomethyl group can be grafted on to the main chain of the polymer [205]. 

X indicates a small substituent, which may be an atom such as hydrogen (H) or chlorine (Cl) or it may he a group such as methyl (CH3), cyano (CN), carhoxyl (COOH), carbomethoxy (COOCH3), etc. The growing chain is terminated by collision with another chain or other radical source or by one of several other mechanisms. The number of monomer units in the polymer chain is the degree of polymerization, abbreviated DP. If the degree of polymerization is very low, the product is sometimes referred to as an oligomer. 

In the 2,5-DSP(a) and P2VB crystals, the directions of three axes of the polymer coincide with those of the monomer whereas a different type of relative orientation is seen in diphenyl- and diethyl 1,4-phenylene diacrylates (3 OPh and 3 OEt), and dipropyl 1,4-(2-cyano)-phenylene diacrylate (4 OPr). 

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