The structures of tricarbonyl(formylcyclopentadienyl)manganese(I),[Mn(C(6)H(5)O)(CO)(3)],(I), and tricarbonyl(formylcyclopentadienyl)rhenium(I),[Re(C(6)H(5)O)(CO)(3)],(II), were determined at 100 K. Compounds (I) and (II) both possess a carbonyl group in a trans position relative to the substituted C atom of the cyclopentadienyl ring, while the other two carbonyl groups are in almost eclipsed positions relative to their attached C atoms. Analysis of the intermolecular contacts reveals that the molecules in both compounds form stacks due to short attractive π(CO)...π(CO) and π(CO)...π interactions, along the crystallographic c axis for (I) and along the [201] direction for (II). Symmetry-related stacks are bound to each other by weak intermolecular C-H...O hydrogen bonds, leading to the formation of the three-dimensional network.

2-Stannyl and 2,6-distannyl naphthalene diimides (NDIs) can be synthesized through the palladium-catalyzed reaction of the appropriate bromo derivatives with hexabutylditin. The utility of these precursors in palladium catalyzed cross-coupling reactions is demonstrated by the synthesis of bi- and ter-NDI derivatives, UV-vis, cyclic voltammetry, and n-channel organic field-effect transistor data for which are compared to those of the monomeric parent NDI.

The synthesis and the antitumor activity and fluorescent properties screening of novel bisphosphonate conjugates with cytotoxic 3,5-bis((hetero)arylidene)-4-piperidone residues were performed. The facile and rapid synthetic route was based on the aza-Michael addition of NH-3,5-bis((hetero)arylidene)-4-piperidones to tetraethyl ethylidenebisphosphonate. The synthesized compounds displayed high inhibitory properties towards Caov3, A549, PC3, and KB 3-1 human carcinoma cell lines. Among those, compounds bearing 4-cyano-phenyl and 3-pyridinyl substituents were revealed as the most active drug candidates with IC(50) values in the range of 0.5-2.5 µM. Methylenebisphosphonate with 4-Me(2) N-C(6) H(4) groups in the piperidone framework possessing fluorescence properties may be of interest for visualization of BPs skeletal distribution and cellular uptake in bones and other tissues.

Several N-alkyl and N,N-dialkylaminomethanesulfonic acids were synthesized (as zwitterions and/or sodium salts) to be tested for utility as biological buffers at lower pH levels than existing Good buffer compounds (aminoalkanesulfonates with a minimum of two carbons between amine and sulfonic acid groups as originally described by Norman Good, and in common use as biological buffers). Our hypothesis was that a shorter carbon chain (one carbon) between the amino and sulfonic acid groups should lower the ammonium ion pK(a) values. The alkylaminomethanesulfonate compounds were synthesized in aqueous solution by reaction of primary or secondary amines with formaldehyde/sodium hydrogensulfite addition compound. The pK(a) values of the ammonium ions of this series of compounds (compared to existing Good buffers) was found to correlate well with the length of the carbon chain between the amino and sulfonate moeties, with a significant decrease in amine basicity in the aminomethanesulfonate compounds (pK(a) decrease of 2 units or more compared to existing Good buffers). An exception was found for the 2-hydroxypiperazine series which shows only a small pK(a) decrease, probably due to the site of protonation in this compound (as confirmed by X-ray crystal structure). X-ray crystallographic structures of two members of the series are reported. Several of these compounds have pK(a) values that would indicate potential utility for buffering at pH levels below the normal physiological range (pK(a) values in the range of 3 to 6 without aqueous solubility problems)- a range that is problematic for currently available Good buffers. Unfortunately, the alkylaminomethanesulfonates were found to degrade (with loss of their buffering ability) at pH levels below the pK(a) value and were unstable at elevated temperature (as when autoclaving)- thus limiting their utility.

A one-pot preparation of the 2,2'-dibromo-1,1'-bisheteroarenes 3a-d from bromo-heteroarenes utilizing the sequence of the base-catalyzed halogen dance (BCHD) reaction and CuCl(2)-promoted oxidative coupling of the in situ formed alpha-lithio-beta-halo-heteroarenes 2a-d provides a convenient access to precursors for the preparation of tricyclic heteroaromatic cores. The structures of 3a,b,d, 6, and 9 were confirmed by single-crystal X-ray analysis, and dibromides 3a and 3b were used for the preparation of dithieno-[2,3-b:3',2'-d]-pyrrole 10a and its selenophene analogue 10b, respectively.

Crystal structures have been determined for six dipolar polyene chromophores with metallocenyl - ferrocenyl (Fc), octamethylferrocenyl (Fc''), or ruthenocenyl (Rc)- donors and strong heterocyclic acceptors based on 1,3-diethyl-2-thiobarbituric acid or 3-dicyanomethylidene-2,3-dihydrobenzothiophene-1,1-dioxide. In each case, crystals were found to belong to centrosymmetric space groups. For one example, polymer-induced heteronucleation revealed the existence of two additional polymorphs, which were inactive in second-harmonic generation, suggesting that they were also centrosymmetric. The bond-length alternations between the formally double and single bonds of the polyene bridges are reduced compared to simple polyenes, indicating significant contribution from charge-separated resonance structures, although the metallocenes are not significantly distorted towards the [(eta(6)-fulvene)(eta(5)-cyclopentadienyl)metal(II)](+) extreme. DFT geometries are in excellent agreement with those determined crystallographically; while the pi-donor strengths of the three metallocenyl groups are insufficiently different to result in detectable differences in the crystallographic bond-length alternations, the DFT geometries, as well as DFT-calculations of partial charges for atoms, suggest that pi-donor strength decreases in the order Fc''>> Fc > Rc. NMR, IR and electrochemical evidence also suggests that octamethylferrocenyl is the stronger pi-donor, exhibiting similar pi-donor strength to a p-(dialkylamino)phenyl group, while ferrocenyl and ruthenocenyl show very similar pi-donor strengths to one another in chromophores of this type.

The electronic properties of the 2,6-diiododithieno[3,2-b:2',3'-d] thiophene molecule and crystal are investigated by means of UV-vis spectroscopy, cyclic voltammetry, X-ray crystallography, and density functional theory. The experimental and calculated properties of the compound are compared to those exhibited by the parent molecule, dithieno[3,2-b:2',3'-d]thiophene. Quantum-chemical studies of the 2,6-diiododithieno[3,2-b:2',3'-d]thiophene crystal suggest uniaxial hole-transport character with an effective mass of about 2m(0), comparable to that in the pentacene single crystal.

In order to design the agents with improved antitumor activity of 3,5-bis(thienylidene)piperid-4-one type, E,E-N-phosphoryl-3,5-bis(thienylidene)piperid-4-ones 6a-c and E,E-N-omega-phosphorylalkyl-3,5-bis-(thienylidene)piperid-4-ones 7a-c were obtained via the direct phosphorylation of the parent NH-3,5-bis(thienylidene)piperid-4-one and by condensation of preformed N-phosphorylalkyl substituted piperidones with thiophene 2-carbaldehyde, respectively. The structures of the compounds were elucidated by (1)H,(31)P,(13)C NMR along with a single crystal X-ray diffraction analysis. Under the action of visible light thermodynamically more stable E,E-isomers slowly undergo photochemical conversion in CDCl(3) solution to the corresponding E,Z-isomers and E,Z-N-methyl-3,5-bis(thienylidene)piperid-4-one 5 was isolated in individual state. The importance of phosphorylation for cytotoxic properties of 3,5-bis(thienylidene)piperid-4-ones towards human carcinoma cell lines Caov3, Scov3, and A549 and influence of olefin configuration on antitumor activity were demonstrated.