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Scientific imaging of a large fragile work of art can be especially challenging, but especially rewarding to better grasp the complexity and changes that have occurred during its creation and lifetime. Here, noninvasive imaging, macro X-ray fluorescence (MAXRF) imaging spectroscopy and reflectance imaging spectroscopy, from the visible to the near infrared spectral range, are utilized to document a 14-m-long Japanese narrative handscroll, The Miraculous Interventions of Jizō Bosatsu. Due to the scroll's age and its handling during past use as a teaching tool, it has a number of conservation needs and shows evidence of past repairs. The scroll has extensive and severe creasing, breaks and tears, as well as unstable and powdering pigments. Microscopic observation and scientific analyses were performed both to document the current condition of the scroll and to better understand its long history. Combining RIS and MAXRF allowed for pigment characterization through elemental and molecular information. While RIS and MAXRF previously have been applied to the study of other painted materials, their application to East Asian paintings is rare. The obstacles of the scroll's length and fragile uneven surface were overcome by optimizing the setups of the two imaging systems. The MAXRF and RIS analyses, here focused on a select scene of the scroll, found certain original pigments common in early Japanese scroll paintings were used frequently, such as vermilion, iron-based compounds (yellow and red ochres), and copper-containing greens, while others occurred sparingly, such as azurite and red lead. A chloride-containing lead-based white pigment was employed. Faded organic colorants, notably indigo as well as an organic yellow/brown, could be detected but their vibrancy has been muted over the centuries. In the case of indigo, it may be visibly observed in some areas; however, analysis revealed its previously unknown presence mixed with a copper green in a select area. This focused study sets a foundation for further studies on both this object and other Asian works of art. [ABSTRACT FROM AUTHOR]

Enantioselective hydrogenation of ketones is a key reaction in organic chemistry. In the past, we have attempted to deal with some unsolved challenges in this arena by introducing chiral tridentate phosphine-diamine/Ru catalysts. New catalysts and new applications are presented here, including the synthesis of phosphine-amino-alcohol P,N,OH ligands derived from (R,S)-1-amino-2-indanol, (S,S)-1-amino-2-indanol and a new chiral P,N,N ligand derived from (R, R)-1,2-diphenylethylenediamine. Ruthenium pre-catalysts of type [RuCl2(L)(DMSO)] were isolated and then examined in the hydrogenation of ketones. While the new P,N,OH ligand based catalysts are poor, the new P,N,N system gives up to 98% e.e. on substrates that do not react at all with most catalysts. A preliminary attempt at realising a new delta lactone synthesis by organocatalytic Michael addition between acetophenone and acrylonitrile, followed by asymmetric hydrogenation of the nitrile functionalised ketone is challenging in part due to the Michael addition chemistry, but also since Noyori pressure hydrogenation catalysts gave massively reduced reactivity relative to their performance for other acetophenone derivatives. The Ru phosphine-diamine system allowed quantitative conversion and around 50% e.e. The product can be converted into a delta lactone by treatment with KOH with complete retention of enantiomeric excess. This approach potentially offers access to this class of chiral molecules in three steps from the extremely cheap building blocks acrylonitrile and methyl-ketones; we encourage researchers to improve on our efforts in this potentially useful but currently flawed process. [ABSTRACT FROM AUTHOR]

This study focuses on the dye analysis of 26 ikat textiles present in the collection of the Arthur M. Sackler Gallery and originally collected by Dr. Guido Goldman with the aim to gain additional information about their provenance and dating. The investigation exploits the full potential of a multi-analytical approach, starting with a non-invasive survey of all the colors using fiber optic reflectance spectroscopy (FORS), which revealed the presence of indigo and insect-based red dyes. These data were used to select areas from which samples were taken and analyzed by high performance liquid chromatography diode array detector (HPLC–DAD). These results enabled most of the natural sources of dyes to be fully identified, including American cochineal (Dactylopius coccus), madder (probably Rubia tinctorum), lac (probably Kerria lacca), larkspur (Delphinum semibarbatum), pagoda tree flower buds (Sophora japonica), grape vine leaves (Vitis vinifera), indigo and tannins. Complex mixtures of dyes were present in most samples, as a result of both the ikat making process itself and traditional dyeing practices. Synthetic dyes were identified in 9 of the textiles. Samples were re-analyzed using HPLC–DAD coupled to mass spectrometry (HPLC–DAD-MS). Malachite green (basic green 4, C.I. 42000), fuchsine (basic violet 14, C.I. 42510), rhodamine B (basic violet 10, C.I. 45170) and methyl violet (basic violet 1, C.I. 42535) were identified, and a few other tentatively identified synthetic dyes (probably orange I, II and IV, rhodamine 6G, patent blue V and alizarin yellow GG) were detected. As the first synthesis of early synthetic dyes is well documented, their presence was used to refine the dating of these textiles. The contextualization of the results also appeared to support the stylistic assumption that more intricate and colorful designs with a higher level of complexity are dated earlier than simpler, larger and more graphic ones. The overall information acquired reveals a dynamic scenario and an interesting window into the dyers' experiments and adjustments to the economic and technological changes of the nineteenth century. [ABSTRACT FROM AUTHOR]