John Anthony Marsella

Hydration of acetylenic compounds without using mercury

Copper(II), palladium(II) and silver(I), in conjunction with non-coordinating anion environments, have been found to catalyze the hydration of a variety of functionalized and nonfunctionalized alkynes. Suitable anions include trifluoromethane sulfonate, tetrafluoroborate, and sulfonate groups on perfluorinated ion-exchange resins. These catalyst systems are the first reported catalysts that are active for the hydration of acetylenic alcohols in high selectivity and do not contain mercury. The problems of dehydration and byproduct formation, observed when other catalysts are used with these alcohols, are minimized.

Ruthenium catalyzed reactions of ethylene glycol with primary amines: steric factors and selectivity control

Abstract The selectivity of reactions of ethylene glycol with primary amines in the presence of RuCl2(PPh3)3 at 120°C is highly dependent on the steric nature of the amine. Selectivity to di-amination is favored by smaller alkyl groups on the amine while large amines cleanly yield ethanolamines. This contrasts with the results obtained with secondary amiens at this temperature, in which ruthenium-triphenylphosphine catalyst systems always favor mono-amination. In the case of sec-butyl amine, where almost equal amounts of mono- and di-aminated product are obtained, the selectivity can be shifted to mon-amination by the addition of excess triphenylphosphine. The steric effects seen in these reactions are consistent with standard steric parameters available from the literature.

Acceleration of amine/epoxy reactions with N‐methyl secondary amines

Kinetic studies established that the monomethylation of a primary amine leads to significantly higher reaction rates with glycidyl ethers. The relative rates for approximately 25 amines were determined in an alcohol solvent under pseudo-first-order conditions (excess epoxy). The rates were referenced to aniline. For the aliphatic amines, reactivity consistently increased upon going from a primary amine to the corresponding N-methyl secondary amine. This acceleration effect was not seen for aniline. The enhanced reactivity was also seen in curing systems, both with pure methylated amine curing agents and with complex mixtures obtained from the partial methylation of polyamines. Economically viable partially methylated amine curing agents were obtained by the reductive alkylation of commercial polyamines with formaldehyde and by the reaction of monomethylamine with 3-(N-methylamino)propionitrile in the presence of hydrogen and a hydrogenation catalyst. Although actual cure performance is based on a complex combination of several factors, the acceleration due to monomethylation could be a useful tool for enhancing amine/epoxy curing reactions.

Ruthenium-catalyzed formation of N-methylformamides from synthesis gas and ammonia

Abstract A number of transition metal carbonyls and oxides have been found to catalyze the reaction of carbon monoxide, hydrogen and ammonia to give formamide, N-methylformamide, N,N-dimethylformamide and trimethylamine. Mono- and dimethylamine were not observed as products. Of the transition metals investigated, compounds of ruthenium provided the most active catalyst solutions. Reactivity studies indicate that methanol is not a viable intermediate for the reaction; however, both added methanol and ethanol participate in parallel reactions to give alkyl formamides and amines. The yields of MMF and DMF are sensitive to the amount of NH3 initially charged to the reactor, with optimal productivities obtained at CO:H2:NH3 ratios of ~3:3:1. Various possible mechanisms are presented.

Hexafluoroisopropyl and trifluoromethyl carbinols in an acrylate platform for 157-nm chemically amplified resists

Electromagnetic radiation in the vacuum-ultraviolet (VUV) region is needed for imaging of very fine features at the 65 nm and 45 nm nodes. Photolithography using 157-nm radiation, emitted from an F2 excimer laser, is a candidate for next generation lithography. Only chemically amplified resists containing fluorinated hydrocarbons and siloxanes have the required transparency at this wavelength. We have identified hexafluoroisopropanol units as a building block for our 157-nm resist polymers. This paper reports our progress on the most recent research development for this platform. The hexafluoroisopropanol functionality, which has a pKa similar to phenol, has been used to increase the transparency of 157-nm single-layer acrylate-based resists. Our recent effort has been focused on the syntheses of new acrylate monomers with highly transparent building blocks based on trifluoroacetone. The first example, a homopolymer derived from trifluoroacetone bearing a fluorinated hemiacetal unit, has moderate transparency at 157 nm (A = 1.9 μm-1). We have also introduced a new acrylate monomer containing a trimer based on trifluoroacetone, where the 6-hydroxy group in the hemiacetal unit is substituted by a fluorine atom, with an acceptable transparency at 157 nm (A = 2.1 μm-1). Copolymers of the former monomer, derived from trifluoroacetone, and tert-butyl α-fluoroacrylate have also been prepared and showed good 248-nm lithographic performance suggesting suitability for 157-nm lithography. This paper will discuss the transparency, etch resistance and chemical properties of several fluorinated acrylate-based resists, synthesized from groups containing pendent hexafluoroisopropanol units and trimers derived from trifluoroacetone.

Wetting and dissolution studies of fluoropolymers used in 157 nm photolithography applications

Photolithography using the F2 excimer laser at 157 nm, a technology to bridge traditional optical lithography and next generation lithographies, promises to enable ultralarge scale integrated devices with sub-70 nm design rules. Chemically amplified resists based on fluoropolymers have previously been shown to be good candidates for 157 nm microlithography. In our research, hexafluoroisopropyl alcohol (HFIPA) groups have been incorporated into polymers to improve the base solubility and to increase the transparency needed for new photoresists at 157 nm. These new polymers have absorbance values at 157 nm ranging from 1.7 to 3.9 μm−1. The introduction of fluorine groups increases their hydrophobicity and makes these polymers more difficult to wet at the surface. We have studied the effect of fluorine content on hydrophobicity of fluorinated polymers by measuring contact angle data over short time intervals. The ability to combine fluoropolymer synthesis with extensive contact angle studies has proven to be...

Novel reactions of quadricyclane: a new route to monomers for low-absorbing polymers in 157-nm photoresists

Norbornene monomers with fluorinated substituents are often used in copolymers targeted for photoresist applications at 157 nm. Homopolymers of these norbornene monomers typically exhibit an absorption coefficient greater than 1.5 μm-1. Comonomers, which are often perfluoroolefins, are needed to meet the transparency requirement for 157 nm lithography, namely an absorption coefficient less than 1.0 μm-1. Clearly, a norbornene monomer that gives a homopolymer with an optical density less than 1.0 μm-1 would require less, if any, perfluoroolefin comonomer, providing a distinct advantage in the production of the base resin. Research in Air Products and Chemicals’ labs has led to the discovery that fluorinated hydroxyalkyl ether derivatives of norbornene ring systems with suitable substitution patterns can give homopolymers with absorption coefficients of less than 1 μm-1. The monomers are produced via a novel reaction pathway involving quadricyclane. This pathway provides a versatile and rich synthetic chemistry, and the potential for eliminating, or at least substantially decreasing, perfluoroolefin incorporation into 157 nm photoresists. Specific examples of these reactions are discussed here, along with VUV-VASE and etch resistance data for a series of polymers derived from quadricyclane reactions.