MacDonald-type conditions

Efforts towards the preparation of porphyrin-functionalized polythiophenes have centered on complexes 38-41, in which thiophenes are tethered to porphyrin cores (Chart 5.9) [50], The syntheses employed either porphyrin formation using MacDonald-type conditions (38-40) or Wittig coupling to produce 41. No electronic properties of these materials have yet been reported. 

With the original reports of the successM synthe of the sapphyrins [26,66,152] and uranyl superphthalocyanine [112, 118, 119], interest in other expanded porphyrin systems, was kindled. The next logical step (after sapphyrin), in the expanding series of all-pyrrole systems, was the pentaphyrin macrocycle 231 which contains five pyrroles and five meso-like methine bridgra. In 1983 Gossauer et al. reported the synthesis of the first prototypical member 231 of this macrocyclic family [158, 182, 183, 185-187]. This first synthesis was achieved by a 2 + 3 MacDonald-type condensation between an oc-firee dipyrromethane 233 and a tripyrrane dialdehyde 236. More recently, the synthesis of pentaphyrin 231 has l n achieve by using a dipyrromethane 5,5 -dicarboxylic acid 235 in place of an a-firee dipyrromethane [21]. Here, as is the case in many of these kind of reactions [21,26,27,66,155], decarboxylation occurs under the reaction conditions to produce the corresponding a-free species 233 in situ. (Scheme 40) [21]. 

The first synthesis of pentaphyrin was reported by Gossauer in 1983. He used an HBr-catalyzed 2 + 3 MacDonald-type condensation between the diformyl tripyrrane 6.29 and the a-free dipyrrylmethane derivative 6.32 to establish the basic macrocyclic framework. Oxidation with chloranil then gave pentaphyrin 6.35 in 31% overall yield (Scheme 6.4.1). Subsequent to this original disclosure, syntheses of pentaphyrins with various other peripheral substituents appeared in the literature (e.g., 6.38 and 6.39). They were all made using this same general procedure." Interestingly, it was found that pentaphyrins could not be prepared when the nucleophilic and electrophilic nature of the reactant dipyrrylmethane and tripyrrane (the 2 and 3 components, respectively) were reversed. This became evident when the diacid tripyrrane 6.38 and the diformyl dipyrrylmethane 6.39 were reacted under conditions identical to those used to prepare pentaphyrin 6.35. Here, only porphyrins, and not pentaphyrins, were obtained (Scheme 6.4.2). " ... 

Experimental studies of the effect of flow rate on the ECP of Types 304SS and Alloy 182 in high-temperature water have been reported by Macdonald et al. [51], on Type 316SS under simulated BWR chemistry conditions by Kim et al. [52, 53], and on Type 304SS by Prein and Molander [54]. In the work of Macdonald et al. [51] tubular flow at low flow rates was employed which, while not simulating the exact conditions in BWR coolant circuits did provide a sensitive test of the MPM. A comparison between experiment and theory is shown in Fig. 21. The experimental... 

Mammalian pheromones can code for a wealth of information including species, subspecies, social group, individuality, sex, age, social status and reproductive conditions (e.g.. Bowers Alexander 1967 Mackintosh 1970 Dagg Windsor 1971 Lydell Doty 1972 Beauchamp 1973 Epple 1973 Miiller-Schwarze 1974 Mertl 1975 Brown 1979 Smith et al. 1985 Passanisi MacDonald 1990 Feoktistova 1995). Traditionally, a pheromone source has been thought to contain one specific type of information. Recent studies have demonstrated that different secretions can carry different information and thus have different functions (Johnston et al. 1993). It is also found that the same secretion may code for different information and thus, serve multiple functions (e.g., Mykytowycz 1965 Quay Muller-Schwarze 1971 Buss et al. 1976 Epple et al 1979 Johnston 1985) or several different secretions carry the same information (Baldwin Meese 1977 Roeder 1980 Martin Beauchamp 1982). Thus, the correspondence between secretions and their functions can be one-to-one, one-to-many, many-to-one, and many-to-many. 

According to linear response theory, the procedure described is valid independent of the particular type of perturbation, e.g., sinusoidal, multi-sinus, step function, Dirac pulse, white noise, etc., provided the system meets the following conditions (Kramers, 1929 de Kronig, 1926 Van Meirhaeghe et al., 1976 Macdonald and Urquidi-Mac-donald, 1985 Urquidi-Macdonald et al., 1986). 

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