Diaminobutane dendrimers

Fig. 13. Pseudorotaxane-terminated dendrimers from diaminobutane-functionalized poly-propylimine dendrimers and CB[6]...

Figure 26.1 Synthetic scheme for polypropylene imine) dendrimers using 1,4-diaminobutane as core...

The first family of polycationic cobaltocenium dendrimers reported in the literature is constituted by four generations of the diaminobutane-based polypropylene amine) dendrimers containing 4, 8, 16, and 32 (compound 7 in Fig. 6.7a) cobaltocenium peripheral units, respectively.41... 

This brief description provides only the simplest overview of the way in which dendrimers can he synthesized. Many variations on this scheme have been explored. For example, one might begin with a core molecule that consists of three functional groups (such as ammonia, NH3) rather than the two functional groups found in 1,4-diaminobutane. One could also provide a direction for the growth of the dendrimer by blocking one or more of the functional groups at... 

The first examples of metallated phosphine-functionalized dendrimers that were suitable as homogeneous catalysts were reported by Reetz et al. [42], DAB-based phosphino dendrimers were synthesized from the commercially available DAB-polypropylene imine dendrimers (DAB = 1,4-diaminobutane) via a double phosphination of the amines with diphenylphosphine and formaldehyde. These dendrimers were loaded with Pd(II) centers by the reaction of the phosphine-functionalized dendrimer with [Pd(Me)2(tmeda)] (tmeda = tetramethylethylenediamine), in which the diphenylphosphino end groups act as a bidentate ligand (Scheme 6). 

With the diaminobutane (DAB) dendrimers formulated G -DAB-dend-(NH2) , amidoferrocenyl [34-42] and pentamethyl-amidoferrocenyl [64,65] dendrimers have been synthesized (Scheme 2) for the five generations from Gi (4 branches) to G5 (theoretical number 64 branches). 

A similar early example of another fifth generation dendrimer that is formed from the reaction of 1,4-diaminobutane, acrylonitrile, a Raney cobalt catalyst and hydrogen is illustrated in Figure 17. Its systemic canonical name is ... 

A similar synthetic approach has also been used to synthesize the corresponding octaferrocenyl derivatives. A series of remarkable ferrocenyl dendritic macromolecules based on flexible poly(propylene-imine) dendrimer cores containing 4, 8, 16, 32, or 64 peripheral ferrocenyl moieties has been prepared via condensation reactions of ferrocene carbonylchloride with the first-, second-, third-, fourth-, and fifth-generation diaminobutane-based... 

S. Hackbarth, V. Homeffer, A. Wiehe, F. Hillenkamp, B. Roder, Photophysical properties of pheophorbide-a-substituted diaminobutane polypro-pylene-imine dendrimer. Chemical Physics 269, 339-346 (2001)... 

High-molecular mass surfactants such as butyl acrylate-butyl methacrylate-methacrylic acid copolymer sodium salts, starburst dendrimers, poly(amidoamines), and diaminobutane-based poly(propyleneimine) as well as cationic polyelectrolytes (ionenes) had all been presented as successful secondary phases for aromatic compounds. The determination of 10 nitrophenols in glycine buffers modified by 3-CD (0-10 mmolL" ) and polyvinylpyrrolidone (PVP) (0.5-2.5% w/v) is an example of application of polymer-based electrolytes to rain, tap, and process water. ... 

Special attention is focused on dendrimers (see Sections 6-4 and 7-6), a new class of regular pol rmers characterized by a tree-type structure, generating from one center, by a great number of branching centers and by the absence of closed rings [83]. Sometimes they are called cascade polymers or polymers with controlled molecular architecture [84], Poly(amidoamine) or poly(propylene-amine) with a diaminobutane nucleus are commonly used for this purpose. In... 

In hydrogenation of dienes to monoenes under mild conditions in various solvents (alcohols, tetrahydrofuran, acetone, dimethylformamide), the catalyst DAB-JenJr-[N(CH2PPh2]i6 (51) and PdCl2(PhCN)2 (DAB dendrimers based on a poly(propylene imine)-diaminobutane core) was much more active than its low molecular weight analogue and proved to be a selective catalyst for hydrogenation of dienes to monoenes [112]... 

Dendrimers based on diaminobutane serve as crosslinking agents for fluo-rinated PI types and are active at room temperature. ... 

L. Shao, T.-S. Chung, S. H. Goh, and K. P. Pramoda. Transport properties of cross-linked polyimide membranes induced by different generations of diaminobutane (DAB) dendrimers. 7. Membr. ScL, 238(1-2) 153-163, July 2004. 

Dendrimers with terminal groups that are modified with pseudorotaxanes were reported. Kim et al. attached diaminobutane units at the terminals of poly-propylimine (PPT) dendrimers (G1-G5), and then threaded CB[6] onto the diaminobutane terminals to produce pseudorotaxane-terminated dendrimers. The structures and properties of the dendrimers can be reversibly changed by threading and dethreading CB[6]. 

---