John H. Thurston

Bio: John H. Thurston is an academic researcher from Rice University. The author has contributed to research in topics: Platinum & Nuclear magnetic resonance spectroscopy. The author has an hindex of 14, co-authored 21 publications receiving 606 citations. Previous affiliations of John H. Thurston include Texas Tech University.

Heterobimetallic Bismuth−Transition Metal Salicylate Complexes as Molecular Precursors for Ferroelectric Materials. Synthesis and Structure of Bi2M2(sal)4(Hsal)4(OR) 4 (M = Nb, Ta; R = CH2CH3, CH(CH3)2), Bi2Ti3(sal)8(Hsal)2, and Bi2Ti4(OiPr)(sal)10(Hsal) (sal = O2CC6H4-2-O; Hsal = O2CC6H4-2-OH)

Abstract: The reactions between triphenylbismuth, salicylic acid, and the metal alkoxides M(OCH2CH3)5 (M = Nb, Ta) or Ti{OCH(CH3)2}4 have been investigated under different reaction conditions and in differen...

Molecular Precursors for Ferroelectric Materials: Synthesis and Characterization of Bi2M2(μ-O)(sal)4(Hsal)4(OEt)2 and BiM4(μ-O)4(sal)4(Hsal)3(OiPr)4 (sal = O2CC6H4O, Hsal = O2CC6H4OH) (M = Nb, Ta)

Abstract: Reactions between triphenyl bismuth, salicylic acid, and niobium or tantalum ethoxide have been explored. Four new coordination complexes incorporating bismuth and the group 5 metals niobium or tantalum have been synthesized and characterized spectroscopically, by elemental analysis, and by single crystal X-ray diffraction. The new complexes are Bi2M2(μ-O)(sal)4(Hsal)4(OEt)2 (1a, M = Nb; 1b, M = Ta) and BiM4(μ-O)4(sal)4(Hsal)3(OiPr)4 (sal = O2CC6H4-2-O, Hsal = O2CC6H4-2-OH) (2a, M = Nb; 2b, M = Ta). Complexes 1a and 1b are isomorphous, as are 2a and 2b. The thermal and hydrolytic decomposition of 1a has been explored by DT/TGA and powder X-ray diffraction, while scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to characterize the morphology and composition of the oxides. The heterobimetallic molecules are completely converted to the amorphous bimetallic oxide by heating to 500 °C in air. Decomposition of 1a or 1b at 650 °C produces the metastable high temperature...

Toward a general strategy for the synthesis of heterobimetallic coordination complexes for use as precursors to metal oxide materials: synthesis, characterization, and thermal decomposition of Bi(2)(Hsal)(6).M(acac)(3) (M = Al, Co, V, Fe, Cr).

Abstract: Bismuth(III) salicylate, [Bi(Hsal)(3)](n), reacts readily with the trivalent metal beta-diketonate compounds M(acac)(3) (acac = acetylacetonate; M = Al, V, Cr, Fe, Co) to produce trinuclear coordination complexes of the general formula Bi(2)(Hsal)(6).M(acac)(3) (M = Al, V, Cr, Fe, Co) in 60-90% yields. Spectroscopic and single crystal X-ray diffraction experiments indicate that these complexes possess an unusual asymmetric nested structure in both solution and solid state. Upon standing in dichloromethane solution, Bi(2)(Hsal)(6).Co(acac)(3) eliminates Bi(Hsal)(3) to give the 1:1 adduct Bi(Hsal)(3).Co(acac)(3). The 2:1 heterobimetallic molecular compounds undergo facile thermal decomposition on heating in air to 475 degrees C to produce heterometallic oxide materials, which upon annealing for 2 h at 700 degrees C form crystalline oxide materials. The synthetic approach detailed here represents a unique, general approach to the formation of heterobimetallic bismuth-based coordination complexes via the coordination of M(acac)(3) complexes to bismuth(III) salicylate.

Heterobimetallic Bi(III)−Ti(IV) Coordination Complexes: Synthesis and Solid-State Structures of BiTi4(sal)6(μ-OiPr)3(OiPr)4, and the Cyclic Isomers Bi4Ti4(sal)10(μ-OiPr)4(OiPr)4 and Bi8Ti8(sal)20(μ-OiPr)8(OiPr)8

Abstract: The reaction of a 1:2 mixture of bismuth(III) salicylate with titanium(IV) isopropoxide in refluxing toluene has been investigated and found to proceed with ligand exchange to produce the new heter...

Nanostructured bimetallic oxide ion-conducting ceramics from single-source molecular precursors

Abstract: A new approach for the formation of bimetallic coordination complexes of bismuth containing a 1:1 ratio of the two metal species has been developed. The strategy exploits the Lewis acidic nature of bismuth and has been used to synthesize the new complexes BiV(O)(Hsal)(sal)(salen*)·CH2Cl2 (1), BiCu(Hsal)3(salen) (2), and BiNi(Hsal)3(salen)·CH2Cl2 (3) (salen = ethylenebis(salicylimine), salen* = ethylenebis(3-methoxysalicylimine), sal = O2CC6H4-2-O, Hsal = O2CC6H4-2-OH). The compounds have been characterized spectroscopically and, in the case of 2 and 3, by single-crystal X-ray diffraction. The decomposition of the bimetallic complexes by both thermal and hydrolytic routes has been investigated. The ability of the compounds to act as single-source precursors for the formation of bimetallic oxides has been explored. Oxide ion-conducting phases have been produced by direct pyrolysis of 1, which results in the formation of monoclinic BiVO4, and by pyrolysis of mixtures of 1 and 2 or 3, which results in isolati...

Secondary building units, nets and bonding in the chemistry of metal–organic frameworks

Abstract: This critical review presents a comprehensive study of transition-metal carboxylate clusters which may serve as secondary building units (SBUs) towards construction and synthesis of metal–organic frameworks (MOFs). We describe the geometries of 131 SBUs, their connectivity and composition. This contribution presents a comprehensive list of the wide variety of transition-metal carboxylate clusters which may serve as secondary building units (SBUs) in the construction and synthesis of metal–organic frameworks. The SBUs discussed here were obtained from a search of molecules and extended structures archived in the Cambridge Structure Database (CSD, version 5.28, January 2007) which included only crystals containing metal carboxylate linkages (241 references).

Hybrid Organic−Inorganic Polyoxometalate Compounds: From Structural Diversity to Applications

Abstract: Polyoxometalates (POMs) are discrete anionic metaloxygen clusters which can be regarded as soluble oxide fragments. They exhibit a great diversity of sizes, nuclearities, and shapes. They are built from the connection of {MOx} polyhedra, M being a d-block element in high oxidation state, usually VIV,V, MoVI, or WVI.1 While these species have been known for almost two centuries, they still attract much interest partly based on their large domains of applications. They play a great role in various areas ranging from catalysis,2 medicine,3 electrochemistry,4 photochromism,5 to magnetism.6 This palette of applications is intrinsically due to the combination of their added value properties (redox properties, large sizes, high negative charges, nucleophilicity...). Parallel to this domain, the organic-inorganic hybrids area has followed a similar expansion during the last 10 years. The concept of organic-inorganic hybrid materials * To whom correspondence should be addressed. E-mail: dolbecq@ chimie.uvsq.fr. Chem. Rev. 2010, 110, 6009–6048 6009

Monoclinic structured BiVO4 nanosheets: hydrothermal preparation, formation mechanism, and coloristic and photocatalytic properties.

Abstract: Bismuth vanadate (BiVO(4)) nanosheets have been hydrothermally synthesized in the presence of sodium dodecyl benzene sulfonate (SDBS) as a morphology-directing template. The nanosheets were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) equipped with an X-ray energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), IR spectroscopy, transmission electron microscopy (TEM), and high-resolution TEM (HR-TEM). The BiVO(4) nanosheets had a monoclinic structure, were ca. 10-40 nm thick, and showed a preferred (010) surface orientation. The formation mechanism and the effects of reaction temperature and time on the products were investigated. UV-visible diffuse reflection spectra indicated that the BiVO(4) nanosheets had outstanding spectral selectivity and improved color properties compared with the corresponding bulk materials. Furthermore, the nanosheets showed good visible photocatalytic activities as determined by degradation of N,N,N',N'-tetraethylated rhodamine (RB) under solar irradiation.

Synthetic Methods for the Preparation of Platinum Anticancer Complexes

Abstract: The demonstration in the 1960's that cis-diamminedichloroplatinum(II), or cisplatin, inhibits cellular division of Escherichia coli1 led to the subsequent discovery that this simple coordination compound is also an effective antitumor agent in mouse models.2 Subsequent studies validated cisplatin as an effective anticancer agent in humans as well,3–7 and FDA approval of cisplatin for the treatment of metastatic ovarian and testicular cancers was granted in 1978.8 Its introduction as a chemotherapeutic agent significantly improved the survival outlook for many cancer patients; the cure rate for testicular cancer before the approval of cisplatin was less than 10%, significantly lower than the 90% cure rate attained with modern platinum chemotherapy.9,10 Cisplatin kills cancer cells primarily by cross-linking DNA and inhibiting transcription.11 The chemical origin of this process begins when cisplatin enters the cell and undergoes aquation involving loss of one or both chloride ligands. The resulting platinum(II) aqua complexes are potent electrophiles that readily react with a number of biological ligands with loss of the bound water molecules. The purine bases of nucleic acids are strongly nucleophilic at the N7 position. Thus, cisplatin binds readily to DNA, forming primarily bifunctional adducts with loss of both chloride ligands. The major cisplatin-DNA adduct is the intrastrand 1,2-d(GpG) cross-link, which accounts for 60–65% of the bound platinum.12 The resulting Pt-DNA adducts, which distort and bend the DNA structure,13–15 impede transcription.16 The downstream effects of transcription inhibition ultimately lead to cell death. Despite its great curative success in testicular cancer, cisplatin is not universally effective in other cancer types and induces a number of toxic side effects.17–19 Additionally, certain cancers are resistant to cisplatin therapy. This resistance is either intrinsic or developed during prolonged treatment.20,21 To circumvent these problems, new platinum complexes have been pursued and investigated for their antitumor properties. Although well over a thousand complexes have been prepared and tested thus far,22 only two other platinum drugs are approved for clinical use worldwide, and three additional compounds are approved for regional use in Asia.23 These complexes, displayed in Chart 1, operate with a mechanism of action similar to that of cisplatin, which involves DNA binding and transcription inhibition. Open in a separate window Chart 1 Chemical structures of the clinically used platinum-based anticancer drugs. The top three complexes, cisplatin, carboplatin, and oxaliplatin, are approved for use worldwide. The bottom three complexes, nedaplatin, lobaplatin, and heptaplatin, are approved for use in Japan, China, and Korea, respectively.