193884-64-9

Upstream product

• 15336-72-8 4,4'-bipiperidine 
• 17201-43-3 4-cyanobenzyl bromide 

Relevant academic research and scientific papers

Silver coordination polymers based on newly designed bis(cyanobenzyl)bipiperidine ligand: Synthesis, anion exchange, guest inclusion, electrochemical, and photoluminescence properties

A new flexible ligand, bis(cyanobenzyl)bipiperidine (L), has been synthesized and structurally characterized. Nine novel silver(I) coordination polymers (CPs), the dimensionality of which depends on the counteranion, [Ag2(L)(NO3)2]n (1), [Ag2(L)(NO3)2]n (2), {[Ag2(L)(NO3)2)](C16H10)}n (3), {[Ag2(L)(NO3)2)](C20H12)}n (4), [Ag2(L)(ClO4)2]n (5), [Ag2(L)(CF3SO3)2(C4H8O)2]n (6), [Ag2(L)(CF3SO3)2(C3H6O)2]n (7), {[Ag2(L)2]·(BF4)·2(C3H6O)}n (8), and [Ag2(L)3(PF6)2]·x(C3H6O) (9), have been prepared by self-assembly of L with AgX (X = NO3-, ClO4-, CF3SO3-, BF4-, and PF6-) and aromatic guest molecules. Reactions of L with AgNO3 in acetone in either 1:2 or 1:1 stoichiometric ratio occurred rapidly at room temperature, yielding topologically different structural isomers of the three-dimensional (3D) CPs 1 and 2. Additional reactions of linker L with AgNO3 in the presence of aromatic guest molecules (pyrene, perylene) formed CPs of 3 and 4 with the inclusion of the corresponding guest in the crystal lattice associated with the reduction of dimensionality of the self-assembled product from 3D to two-dimensional (2D). Reaction of L with AgTf (Tf = CF3SO3-) in acetone and THF gave two structurally related 2D CPs (6 and 7). Compound 8 represents a one-dimensional (1D) coordination polymer where the BF4 anions are not linked to the silver nodes, while 9 is a discrete coordination complex. Anion exchange accompanying an irreversible structural conversion from 7 to 1 and 7 to 8 was monitored in the crystalline state by IR and PXRD techniques. On the other hand, a reversible anion exchange process was observed between 1 and 8. The electrochemical and solid-state photoluminescence properties of these Ag(I) CPs were also characterized.

Design and analysis of molecular motifs for specific recognition of RNA

Selective targeting of RNA has become a recent priority in drug design strategies due to the emergence of retroviruses, the need for new antibiotics to counter drug resistance, and our increased awareness of the essential role RNA and RNA structures play in the progression of disease. Most organic compounds known to specifically target RNA are complex, naturally occurring antibiotics that are difficult to synthesize or derivatize and modification of these compounds to optimize interactions with structurally unique RNAs is difficult. The de novo design of synthetically accessible analogues is one possible alternative; however, little is known about the RNA recognition principles on which to design new compounds and limited information on RNA structure in general is available. To contribute to the growing body of knowledge on RNA recognition principles, we have prepared two series of polycationic RNA-binding agents, one with a linear scaffold, the other with a macrocyclic scaffold. We evaluated these compounds for their ability to bind to DNA and RNA, as well as to a specific RNA, the regulatory sequence, RRE, derived from HIV-1, by using thermal melting, circular dichroism, and electrophoresis gel shift methods. Our results suggest that cationic charge centers of high pK(a) that are displayed along a scaffold of limited nexibility bind preferentially to RNA, most likely within the major groove. Related derivatives that bind more strongly to DNA more closely mimic classical DNA minor-groove binding agents. Several of the macrocyclic polycations expand on a new binding motif where purine bases in duplex RNA are complexed within the macrocyclic cavity, enhancing base-pair opening processes and ultimately destabilizing the RNA duplex. The results in this report should prove a helpful addition to the growing information on molecular motifs that specifically bind to RNA.