David George Churchill

A fluorescent dinuclear zinc complex (1) has been prepared by an easy "one pot" method in which the lysine-based Schiff base ligand is generated in situ. The compound is characterized in detail by various spectroscopic techniques and single-crystal X-ray diffraction. Crystal data: monoclinic, C2, a = 18.31(13) A, b = 8.45(7) A, c = 11.20(8) A, beta = 90.11(6) degrees, V = 1733.6(2) A(3). Z = 2, R1 = 0.0442, wR2 = 0.1068, Flack(x) parameter = 0.03(2). Compound 1 is highly fluorescent, in both the

Annulated BODIPY chalcogenide (Se, Te) systems were synthesized from their respective bis(o-formylphenyl)dichalcogenide intermediates. The annulated BODIPY selenide product was confirmed by X-ray diffraction. The red-shifted telluride version was found to be sensitive and selective for hypochlorite detection, reversible upon treatment with biothiols.

The development of novel fluorescent probes for monitoring the concentration of various biomolecules in living systems has great potential for eventual early diagnosis and disease intervention. Selective detection of competitive species in biological systems is a great challenge for the design and development of fluorescent probes. To improve on the design of fluorescent coumarin-based biothiol sensing technologies, we have developed herein an enhanced dual emission doubly activated system ( DAC

The overall reductive elimination of RH from the ansa-molybdenocene and -tungstenocene complexes [Me(2)Si(C(5)Me(4))(2)]Mo(Ph)H and [Me(2)Si(C(5)Me(4))(2)]W(R)H (R = Me, Ph) is characterized by an inverse primary kinetic isotope effect (KIE) for the tungsten system but a normal KIE for the molybdenum system. Oxidative addition of PhH to [[Me(2)Si(C(5)Me(4))(2)]M] also differs for the two systems, with the molybdenum system exhibiting a substantial intermolecular KIE, while no effect is observed

Access to the [Me 2 Si] ansa -bridged permethylmolybdenocene system is provided by the synthesis of [Me 2 Si(C 5 Me 4 ) 2 ]MoCl 2 from the reaction of MoCl 5 with a mixture of [Me 2 Si(C 5 Me 4 ) 2 ]Li 2 and NaBH 4, followed by treatment with CHCl 3 . Comparison with the chemistry of the non- ansa Cp* 2 MoX 2 system indicates that incorporation of the [Me 2 Si] ansa bridge promotes intermolecular C−H and C−C bond activation reactions.

Fluorescent dinuclear chiral zinc complexes were synthesized in a "one-pot" method in which the lysine-based Schiff base ligand was generated in situ. This complex acts as a highly sensitive and selective fluorescent ON-OFF probe for Cu(2+) in water at physiological pH. Other metal ions such as Hg(2+), Cd(2+), and Pb(2+) gave little fluorescence change.

Real-time strategy video games have proven to be a very challenging area for applications of artificial intelligence research. With their vast state and action spaces and real-time constraints, existing AI solutions have been shown to be too slow, or only able to be applied to small problem sets, while human players still dominate RTS AI systems. This paper makes three contributions to advancing the state of AI for popular commercial RTS game combat, which can consist of battles of dozens of uni

A phenyl-selenium-substituted coumarin probe was synthesized for the purpose of achieving highly selective and extremely rapid detection of glutathione (GSH) over cysteine (Cys)/homocysteine (Hcy) without background fluorescence. The fluorescence intensity of the probe with GSH shows a ∼100-fold fluorescent enhancement compared with the signal generated for other closely related amino acids, including Cys and Hcy. Importantly, the substitution reaction with the sulfhydryl group of GSH at the 4-p

Heuristic search has been very successful in abstract game domains such as Chess and Go. In video games, however, adoption has been slow due to the fact that state and move spaces are much larger, real-time constraints are harsher, and constraints on computational resources are tighter. In this paper we present a fast search method — Alpha-Beta search for durative moves— that can defeat commonly used AI scripts in RTS game combat scenarios of up to 8 vs. 8 units running on a single core in under

Two novel fluorescent probe conjugates of 2-(benzothiazol-2-yl)-phenol (HBT) enable ratiometric and selective superoxide detection by an established excited state intramolecular proton transfer (ESIPT) mechanism giving a 60-fold intensity increase.

A diselenide-based BODIPY probe was prepared; it was found to be sensitive and selective for superoxide in giving [-Se(O)Se(O)-] oxidation. Probing was reversible through the use of biothiols; (77)Se NMR and other types of spectroscopy were employed. Practical medicinal utility was demonstrated in MCF-7/ADR cancer cells.

Two closely related phenyl selenyl based boron-dipyrromethene (BODIPY) turn-on fluorescent probes for the detection of hypochlorous acid (HOCl) were synthesized for studies in chemical biology; emission intensity is modulated by a photoinduced electron-transfer (PET) process. Probe 2 intrinsically shows a negligible background signal; however, after reaction with HOCl, chemical oxidation of selenium forecloses the PET process, which evokes a significant increase in fluorescence intensity. The fl

In recent years, real-time strategy (RTS) games have gained interest in the AI research community for their multitude of challenging subproblems — such as collaborative pathfinding, effective resource allocation and unit targeting, to name a few. In this paper we consider the build order problem in RTS games in which we need to find concurrent action sequences that, constrained by unit dependencies and resource availability, create a certain number of units and structures in the shortest possibl

We have synthesized and fully characterized three novel, yet closely related, heterocyclically meso-substituted (BODIPY) fluorophores 4,4-difluoro-8-(C(4)H(3)X)-4-bora-3a,4a-diaza-s-indacene (X = O, 2-/3-furyl (7/10); Se, 2-selenenyl (9)) through the use of 2-D NMR (COSY, HSQC, and HMBC), single crystal X-ray diffraction, mass spectrometry, elemental analysis, UV-vis spectroscopy, and fluorescent decay lifetimes, for comparison to the previously reported thienyl species (X = S, 2-/3-thienyl (8/1

Detection of nerve agent-related molecules based on BODIPY-salicylaldehyde oxime conjugation was studied. Fluorescence intensity of the B-SAL-OXIME species increases in the presence of DECP, whereas it decreases in the presence of DCP and DEMP (limit of detection = 997 nM). Benzonitrile formation in the novel fluorescent B-SAL-OXIME system was elucidated using model substrates.