High benzene selectivity of uniform sub-nanometre pores of self-ordered mesoporous silicate

The high benzene gas selectivity of mesoporous silicate (SBA-15) was observed in the sub-nanometre micropore condensation region. The benzene/toluene ratios of the adsorbed amount were >100 and >6 in ideal and pseudo-atmospheric environments, respectively.     

Physical and rheological characterization of poly(aryloxyphosphazene) copolymers

A series of poly(aryloxyphosphazene)s was prepared with phenoxy and p-ethylphenoxy substituents in various ratios. The thermal, morphological, and rheological properties of this series of polymers were studied by differential thermal analysis, x-ray analysis, and rheometrics mechanical spectroscopy. Thermal analysis showed that the resulting polymers follow melting-point-depression- and glass-transition-temperature-composition relationships expected of random copolymers. The lower first-order transition temperature [T(1)] disappears near equimolar substitution while the higher first-order transition temperature (T_m) persists over the whole range of compositions. X-ray analysis revealed that crystalline order in the polymer chain direction is destroyed by nearly equimolar substitution but lateral order remains. The rheological characterization of a copolymer with nearly equimolar substitution showed that the polymer is in a pseudocrosslinked state indicating the existence of chain-to-chain interactions. When a small amount of an antioxidant (6-dodecyl-1,2-dihydro-2,2,4-trimethylquinoline) is added, the lateral order of the copolymer is destroyed, and its rubbery plateau modulus decreases by several fold.     

Multifunctional Reagents for Quantitative Proteome‐Wide Analysis of Protein Modification in Human Cells and Dynamic Profiling of Protein Lipidation During Vertebrate Development

Novel multifunctional reagents were applied in combination with a lipid probe for affinity enrichment of myristoylated proteins and direct detection of lipid‐modified tryptic peptides by mass spectrometry. This method enables high‐confidence identification of the myristoylated proteome on an unprecedented scale in cell culture, and allowed the first quantitative analysis of dynamic changes in protein lipidation during vertebrate embryonic development.     

Substituent positional variations and the lithographic properties of poly(methylstyrene-CO-chloromethylstyrene) resist systems

The lithographic performances of structurally different copolymers of methylstyrene (ortho-, meta- and para-isomers) and chloromethylstyrene (meta- and para-isomers) have been assessed. Linear correlations of the data, based on Charlesby's theory of radiation-induced crosslinking of polymers, demonstrate that sensitivity and contrast are functionally related for this system. Variation of the structure of the chloromethylstyrene component of the copolymers had little effect on the lithographic parameters, but the effect of structural variation of the methylstyrene component was pronounced, the order of increasing sensitivity being ortho < meta < para.     

Modular synthesis of unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene molecular semiconductors for organic transistors

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene (BTBT) scaffolds delivers a library of BTBT materials from readily available coupling partners by combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction. This effective approach to unsymmetrical BTBT materials has allowed their properties to be studied. In particular, tuning the functional groups on the BTBT scaffold allows the solid-state assembly and molecular orbital energy levels to be modulated. Investigation of the charge transport properties of BTBT-containing small-molecule:polymer blends revealed the importance of molecular ordering during phase segregation and matching the highest occupied molecular orbital energy level with that of the semiconducting polymer binder, polyindacenodithiophene-benzothiadiazole (PIDTBT). The hole mobilities extracted from transistors fabricated using blends of PIDTBT with phenyl or methoxy functionalized unsymmetrical BTBTs were double those measured for devices fabricated using pristine PIDTBT. This study underscores the value of the synthetic methodology in providing a platform from which to study structure–property relationships in an underrepresented family of unsymmetrical BTBT molecular semiconductors.

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene (BTBT) scaffolds, combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction, delivers a library of BTBT materials.     

Structural and bonding aspects of molybdenum tricarbonyl complexes of 2,4,6-tritertiarybutyl-1,3,5-triphosphabenzene,P3C3But3 and some λ3,λ3,λ5- and λ3,λ5,λ5-alkylated derivatives

The molecular structure of the previously reported compound [Mo(CO)₃(η⁶-P₃C₃Bu^t₃)] has been determined by a single-crystal X-ray diffraction study. Syntheses and molecular structures are also described for the structurally related compounds [Mo(CO)₃(η⁵-P₃C₃Bu^t₃)(Me)(Buⁿ)], [Mo(CO)₃(η⁵-P₃C₃Bu^t₃)(H)(Buⁿ)] and [Mo(CO)₃(η⁴-P₃C₃Bu^t₃(Me)(Buⁿ)(H)(O)Li(THF)₃]. Density functional calculations at the B3LYP/cc-pVDZ(-PP) and BP86/cc-pVDZ(-PP) levels have been carried out on the above complexes and the nature of the bonding between the different rings and molybdenum is discussed. ³¹P NMR spectroscopic evidence is presented for the existence of the novel complex [Mo(CO)₃(η⁶-P₃C₃Bu^t₃)PtCl₂(PEt₃)] in which the triphosphabenzene ring acts as an overall 8-electron donor to the two metal centres.     

Encapsulation of hydride by molecular main group metal clusters: manipulating the source and coordination sphere of the interstitial ion

The sequential treatment of Lewis acids with N,N'-bidentate ligands and thereafter with ButLi has afforded a series of hydride-encapsulating alkali metal polyhedra. While the use of Me3Al in conjunction with Ph(2-C5H4N)NH gives Ph(2-C5H4N)NAlMe2 and this reacts with MeLi in thf to yield the simple 'ate complex Ph(2-C5H4N)NAlMe3Li.thf, the employment of an organolithium substrate capable of beta-hydride elimination redirects the reaction significantly. Whereas the use of ButLi has previously yielded a main group interstitial hydride in which H- exhibits micro6-coordination, it is shown here that variability in the coordination sphere of the encapsulated hydride may be induced by manipulation of the organic ligand. Reaction of (c-C6H11)(2-C5H4N)NH with Me3Al/ButLi yields [{(c-C6H11)(2-C5H4N)N}6HLi8]+[(But2AlMe2)2Li]-, which is best viewed as incorporating only linear di-coordination of the hydride ion. The guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) in conjunction with Me2Zn/ButLi yields the micro8-hydride [(hpp)6HLi8]+[But3Zn]-.0.5PhMe. Formation of the micro8-hydride [(hpp)6HLi8]+[ButBEt3]- is revealed by employment of the system Et3B/ButLi. A new and potentially versatile route to interstitial hydrides of this class is revealed by synthesis of the mixed borohydride-lithium hydride species [(hpp)6HLi8]+[Et3BH]- and [(hpp)6HLi8]+[(Et3B)2H]- through the direct combination of hppLi with Et3BHLi.     

A highly enantioselective total synthesis of (+)-goniodiol

A high-yielding enantioselective total synthesis of the bioactive styryllactone (+)-goniodiol has been realised, starting from readily available (S)-glycidol. A key step is an oxygen-to-carbon rearrangement of a silyl enol ether linked via an anomeric centre, facilitating the rapid and diastereoselective construction of this functionalised system.