ABSTRACT
2-[2-benzothiazoylmethyl)thio]-benzenamine, which was first reported in 1898, was isolated from the reaction of bromoacetyl bromide and 2-aminothiophenol [1]. The product crystallized from an aqueous methanol solution of the reaction mixture to which nickel(II) acetate had been added. 2-[(2-benzothiazolylmethyl)thio]-benzenamine crystallized in the monoclinic system, in space group C2/c, with cell dimensions of a = 27.392 (19) Å, b = 4.730 (3) Å, and c = 23.686 (16) Å, ß = 122.465 (6)°, V = 2589(3) Å(3), Z = 8 and refined to R = 0.0343 and R(w) = 0.0844. Crystallization from methanol yielded the product as the hydrobromide salt in the monoclinic space group Cc, with cell dimensions of a = 10.488 (3) Å, b = 33.404 (9) Å, c = 5.2578 (14) Å, ß = 116.769(2)°, V = 1644.7(8) Å(3), Z = 4 and refined to R = 0.0296 and R(w) = 0.0600. Mass spectral and NMR analyses confirmed that the bulk and crystalline compound were all 2-[(2-benzothiazolylmethyl)thio]-benzenamine.
ABSTRACT
Radiometals play an important role in diagnostic and therapeutic radiopharmaceuticals. This field of radiochemistry is multidisciplinary, involving radiometal production, separation of the radiometal from its target, chelate design for complexing the radiometal in a biologically stable environment, specific targeting of the radiometal to its in vivo site, and nuclear imaging and/or radiotherapy applications of the resultant radiopharmaceutical. The critical importance of inorganic chemistry in the design and application of radiometal-containing imaging and therapy agents is described from a historical perspective to future directions.
ABSTRACT
Microsolvation of the neutral, zwitterion, and unconventional zwitterion (formed by the proton transfer from the thiol to the amine group) was performed using PBE1PBE/6-311+G(d,p) calculations. A large sampling of the configurations of the clusters involving one to six water molecules was created by analogy to glycine clusters and through analysis of hydrogen-bonding trends. Clusters of the neutral tautomer are lowest in energy with the inclusion up to five water molecules. With six water molecules the neutral and zwitterion are nearly isoenergetic. The unconventional zwitterion, while a stable structure when at least one water molecule is associated with it, remains energetically noncompetitive with the other two tautomers regardless of the degree of microsolvation.
Subject(s)
Cysteine/chemistry , Quantum Theory , Solvents/chemistry , Models, Molecular , Molecular Conformation , Thermodynamics , Vibration , Water/chemistryABSTRACT
B3LYP/6-31+G(d) and MP2/6-31+G(d) computations were performed on a series of ethynyl- and diethynyl-expanded tetrahedranes, prismanes, cubanes and adamantanes. Every ethynyl expansion reduces the ring strain energy of the cage. The deprotonation energies of the cage poly-ynes are exceptionally low; we estimate that the gas-phase deprotonation energy of the diethynyl-expanded cubane is about 309 kcal mol(-1). The ring and cage poly-ynes can serve as effective hosts of either lithium or sodium cation, where the best host maximizes the number of interactions of alkynyl groups with the cation at an ideal distance. Last, the vertical excitation energies of the poly-ynes and their conjugate bases suggest that the alkynyl groups are interacting through space. The poly-ynes express a broad range of absorption energies, indicating that these molecules are potential targets in expressly designed optical applications.
