Codeposition technique

In the early 1980s, Siehl and co-workers319,320 prepared two allenylmethyl cations 120 and 121 using the codeposition technique developed by Saunders et al.49 The cations thus prepared also exhibit extensive mesomeric vinyl cation character. 

In this work, we describe the synthesis and characterization of SWNT/PANI composite films with SWNT incorporated into PANI matrix via electrochemical composite codeposition technique during electropolymerization. The SWNT/PANI composite film modified by electrochemically depositing platinum subsequently shows much higher mass activity and long-term stability for formaldehyde oxidation than a pure PANI film. 

Several methods and variations have been developed to electrodeposit compounds. Most of the work described in this article concerns the formation of nonoxide compounds such as II-VI and in Vs. Oxides are probably the largest group of electrodeposited compounds (aluminum anodization for example), but will not be discussed here. The electrodeposition of H-VI compounds has been extensively studied and is well reviewed in a number of articles [24-29], The most prominent compound electrodeposition methods include codeposition, precipitation, and various two-stage techniques. 

Alternatively PAA can be obtained without solvent by vapor deposition polymerization as described first by Salem et al. [2], In this technique the dianhydride py-romellitic and the dianhydride diamine (4,4 -oxidianiline) are codeposited onto a substrate, where they react to form PAA. Again the transformation to Polyimide is obtained by subsequent heating to temperatures up to 350°C. By comparison to spun dn films, initial interaction of the polymer with the substrate occurs in the uncomplexed PAA state. The chemical interaction between PAA and the metal establishes the adhesion of the final polyimide film. This is discussed in this communication for evaporated gold cluster and bulk silver surfaces. 

The use of carbon in ITER will lead to tritium co-deposition, and operational availability of the machine will depend on the actual tritium codeposition rate and the availability of reliable tritium co-deposition mitigation and/or removal techniques, which still need to be developed. An important uncertainty, which is being addressed by R D, is the consequence of mixing of eroded materials, which will unavoidably occur and, in particular, whether the deposition of eroded Be from the wall at the target plate could reduce substantially the chemical erosion of carbon near the strike points and, thus, tritium co-deposition. 

The matrix codeposition of CsF with HF (31,32) in an excess of argon, up to Ar/HF ratios of 3000, yielded intense bands at 1364 and 1218 cm, within a few wavenumbers of the HF2 band positions in ionic lattices 29]. The deuterium shift, upon formation of DF2, was slightly above the harmonic value of 1.41, indicating that the anion maintained a center of symmetry. Similar results were obtained with other alkali fluoride salts, but the product yield decreased as the radius of the alkali metal cation decreased. These results provided immediate confirmation of the salt/molecule technique, demonstrating that for a known system ion pair formation occurred and that the spectrum of the product anion resembled closely that of the anion in known environments. 

The macroscale codeposition of PF3 has yielded a series of M-PF3 complexes. Some of these M-PF3 complexes can only be prepared by the metal vapor-ligand cocondensation technique. Very electron-rich M-phosphine and M-phosphite derivatives have been prepared by M-PMe3 and M-P(OMe)3 depositions, as shown in Table 8. A series of new homoleptic compounds have been prepared. Cocondensation of Fe and Ni with some arene systems gives stable (Ar)2Fe/Ni species, if maintained at low temperatures. 

---