Log in

Relevant bibliographies by topics / Long chain phosphines / Journal articles

Journal articles on the topic 'Long chain phosphines'

To see the other types of publications on this topic, follow the link: Long chain phosphines.

Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 35 journal articles for your research on the topic 'Long chain phosphines.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Petrucci, Maria G. L., and Ashok K. Kakkar. "Heterogenizing Homogeneous Catalysis Using Molecular Self-Assembly of Long Alkane Chain Phosphines Bound to Rh(I) Complexes." Chemistry of Materials 11, no. 2 (February 1999): 269–76. http://dx.doi.org/10.1021/cm9804968.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Demizu, Kei, Hiroyuki Ishigaki, Hideo Kakutani, and Fukuzo Kobayashi. "The Effect of Trialkyl Phosphites and Other Oil Additives on the Boundary Lubrication of Ceramics: Friction of Silicon-Based Ceramics." Journal of Tribology 114, no. 4 (October 1, 1992): 653–58. http://dx.doi.org/10.1115/1.2920932.

Full text

Abstract:

In order to examine the fundamental boundary lubrication properties of ceramics, reciprocating friction experiments of silicon based ceramics such as silicon carbide and silicon nitride were conducted with trialkyl phosphites and other oil additives. When ceramics were slid against ceramics, trialkyl phosphites with long carbon chains reduced the friction of silicon nitride markedly; the friction coefficients decreased with an increase in the carbon chain length. Other oil additives, however, did not greatly affect the friction. When ceramics were slid against metals, additives containing chlorine or sulfur increased friction of certain sliding couples. On the other hand, a trialkyl phosphite reduced friction and the friction coefficients increased with an increase in the maximum Hertzian contact pressure.

APA, Harvard, Vancouver, ISO, and other styles

3

Il’in, Anton, Arthur Gubaev, Anna Antonova, Arthur Khannanov, and Vladimir Galkin. "Phosphine catalyzed addition of long-chain dialkyl phosphites to electron-deficient alkenes." Synthetic Communications 50, no. 21 (July 30, 2020): 3287–97. http://dx.doi.org/10.1080/00397911.2020.1799015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Corfield, Peter W. R. "Crystal structure of poly[(μ3-thiocyanato-κ3N:S:S)(trimethylphosphine sulfide-κS)copper(I)]." Acta Crystallographica Section E Structure Reports Online 70, no. 11 (October 4, 2014): 281–85. http://dx.doi.org/10.1107/s1600536814021412.

Full text

Abstract:

In the title compound, [Cu(NCS)(C3H9PS)]n, the thiocyanate ions bind the CuIatoms covalently, forming infinite –Cu—SCN—Cu– chains parallel to theaaxis. Each CuIatom is also coordinated to a trimethylphosphine sulfide groupviaa Cu—S bond. Two crystallographically independent chains propagate in opposite directions, and are held together in a ribbon arrangement by long bonds between CuIatoms in the first chain and thiocyanate S atoms in the second, with Cu—S = 2.621 (1) Å. The geometry around the CuIatoms in the first chain is distorted tetrahedral, with angles involving the long Cu—S bond much less than ideal, and the S—Cu—N angle between the phosphine sulfide S atom and the thiocyanate N atom opening out to 133.19 (9)°. Each CuIatom in the second chain appears to be disordered between two positions 0.524 (4) Å apart, with occupancy factors of 0.647 (6) and 0.353 (6). The CuIatom in the major site is in a distorted trigonal–planar configuration, with the S—Cu—N angle between the phosphine sulfide and the thiocyanate N atom again opened out, to 137.01 (15)°. The CuIatom in the minor site, however, forms in addition a long bond [Cu—S = 2.702 (5) Å] to the phosphine sulfide of the first chain, not the thiocyanate S atom, to provide a further link between the chains.

APA, Harvard, Vancouver, ISO, and other styles

5

Soulivong, Daravong, Dominique Matt, Jack Harrowfield, and Loïc Toupet. "A Long-Chain Phosphine Designed as a Metallomesogen Generator—Synthesis and Coordination Properties." Australian Journal of Chemistry 57, no. 2 (2004): 157. http://dx.doi.org/10.1071/ch03264.

Full text

Abstract:

The long-chain phosphine Me2PC≡C(p-C6H4CHNR C8) [L; RC8 = p-C6H4OC(O)(p-C6H4OC8H17)] has been prepared in two steps starting from 4-ethynylbenzaldehyde (1): (a) condensation of 1 with H2NRC8 (2) afforded the corresponding imine 3 (yield 86%) which displays liquid-crystalline behaviour; (b) deprotonation of 3 with LiNPri2 and subsequent reaction with Me2PCl gave a mixture of the phosphine–alkyne L and the precursor 3 (L : 3 = 60 : 40). Reaction of this mixture with [PtCl2(PhCN)2] produced cis-[PtCl2L2] (4) and provided an efficient means of separating the phosphine from 3. The crystal structure of imine 3 has been determined by single-crystal X-ray diffraction and analysis of this structure provides a basis for understanding both the mesogenic character of 3 and its absence in the complex 4.

APA, Harvard, Vancouver, ISO, and other styles

6

Qi, LIN, FU Hai-Yan, XUE Fang, YUAN Mao-Lin, CHEN Hua, and LI Xian-Jun. "Hydroformylation of Long-chain Olefins Catalyzed by Rhodium-Phosphine Complexes in New Ionic Liquids." Acta Physico-Chimica Sinica 22, no. 04 (2006): 465–69. http://dx.doi.org/10.3866/pku.whxb20060415.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Romanova, Irina P., Andrei V. Bogdanov, Inessa A. Izdelieva, Vasily A. Trukhanov, Gulnara R. Shaikhutdinova, Dmitry G. Yakhvarov, Shamil K. Latypov, et al. "Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells." Beilstein Journal of Organic Chemistry 10 (May 14, 2014): 1121–28. http://dx.doi.org/10.3762/bjoc.10.111.

Full text

Abstract:

An easy, high-yield and atom-economic procedure of a C60 fullerene modification using a reaction of fullerene C60 with N-alkylisatins in the presence of tris(diethylamino)phosphine to form novel long-chain alkylindolinone-substituted methanofullerenes (AIMs) is described. Optical absorption, electrochemical properties and solubility of AIMs were studied. Poly(3-hexylthiophene-2,5-diyl) (P3HT)/AIMs solar cells were fabricated and the effect of the AIM alkyl chain length and the P3HT:AIM ratio on the solar cell performance was studied. The power conversion efficiencies of about 2% were measured in the P3HT/AIM devices with 1:0.4 P3HT:AIM weight ratio for the AIMs with hexadecyl and dodecyl substituents. From the optical and AFM data, we suggested that the AIMs, in contrast to [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), do not disturb the P3HT crystalline domains. Moreover, the more soluble AIMs do not show a better miscibility with the P3HT crystalline phase.

APA, Harvard, Vancouver, ISO, and other styles

8

Fu, Haiyan, Min Li, Jun Chen, Ruimin Zhang, Weidong Jiang, Maolin Yuan, Hua Chen, and Xianjun Li. "Application of a new amphiphilic phosphine in the aqueous biphasic catalytic hydroformylation of long chain olefins." Journal of Molecular Catalysis A: Chemical 292, no. 1-2 (September 2008): 21–27. http://dx.doi.org/10.1016/j.molcata.2008.06.005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Fetouaki, Rachid, Annekathrin Seifert, Mona Bogza, Thomas Oeser, and Janet Blümel. "Synthesis, immobilization, and solid-state NMR of new phosphine linkers with long alkyl chains." Inorganica Chimica Acta 359, no. 15 (December 2006): 4865–73. http://dx.doi.org/10.1016/j.ica.2006.07.094.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

She, Xing-jin, Qiang Zhang, Cai-Feng Wang, and Su Chen. "New insights into the phosphine-free synthesis of ultrasmall Cu2−xSe nanocrystals at the liquid–liquid interface." RSC Advances 5, no. 110 (2015): 90705–11. http://dx.doi.org/10.1039/c5ra18313h.

Full text

Abstract:

A liquid–liquid interfacial strategy to prepare ultra small (<5 nm) colloidal Cu₂₋xSe NCs with blue-fluorescence, noncaustic and environmentally friendly NH₄SCN replaces the long-chain organic ligands for fabrication of NC-sensitized solar.

APA, Harvard, Vancouver, ISO, and other styles

11

Liu, Yan-li, Jian-gui Zhao, Yuan-jiang Zhao, Hui-Min Liu, Hai-yan Fu, Xue-li Zheng, Mao-lin Yuan, Rui-xiang Li, and Hua Chen. "Homogeneous hydroformylation of long chain alkenes catalyzed by water soluble phosphine rhodium complex in CH3OH and efficient catalyst cycling." RSC Advances 9, no. 13 (2019): 7382–87. http://dx.doi.org/10.1039/c8ra08787c.

Full text

Abstract:

Hydroformylation of long-chain alkenes proceeded homogeneously in methanol efficiently. The catalyst could be separated heterogeneously when methanol was removed and recycled for four times without obvious loss in catalytic performance and rhodium.

APA, Harvard, Vancouver, ISO, and other styles

12

Chitnis, Saurabh S., and Neil Burford. "ChemInform Abstract: Phosphine Complexes of Lone Pair Bearing Lewis Acceptors." ChemInform 46, no. 7 (January 29, 2015): no. http://dx.doi.org/10.1002/chin.201507290.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Song, Lifang, Huiwen Huo, Wenshuo Zhang, Huiyun Xia, and Yanhui Niu. "The Facile Strategy of Improving the Long-Term Stability of Highly Transparent Polyvinyl Chloride by Introducing Unsaturated Zn Oleate and Uracil Derivatives." Materials 15, no. 7 (April 5, 2022): 2672. http://dx.doi.org/10.3390/ma15072672.

Full text

Abstract:

In order to improve the initial color and the long-term heat stability of super-transparent polyvinyl chloride (PVC), a series of composite heat stabilizers consisting of unsaturated Zn oleate and uracil derivatives have been designed in this paper. The uracil derivatives are 1,3-dimethyl-6-amino-uracil (DAU) and 6,6′-diamino-1,1′,3,3′-tetramethyl-5,5′-(ethylidene)bisuracil (OSU). The static thermal stability, dynamic thermal stability, and transparency were used to evaluate the properties of the stabilized transparent PVC sheets. The results indicate that the compatibility between the stabilizer and PVC was greatly enhanced by introducing an unsaturated long-chain Zn oleate and a long alkyl chain bisuracil derivative. Through the thermal discoloration test, the best ratio of DAU/zinc oleate (DAU/Zn) and OSU/zinc oleate (OSU/Zn) was determined to be 4:1, with a total amount of 3 phr in 100 phr PVC. It was verified that the combination of zinc oleate with uracil derivatives could improve the long-term thermal stability of PVC, and the DAU/Zn was better than that of the OSU/Zn. In addition, through the transmission/haze verification, adding a proper amount of epoxidized soybean oil (ESBO) and phosphite ester to the OSU/Zn system has a certain synergistic effect. The thermal stability and transparency of PVC can be remarkably enhanced.

APA, Harvard, Vancouver, ISO, and other styles

14

Barratt, David S., George A. Gott, and Charles A. McAuliffe. "The co-ordination of small molecules by manganese(II) phosphine complexes. Part 11. The co-ordination of dioxygen by manganese(II) complexes containing long-chain phosphine ligands." Journal of the Chemical Society, Dalton Transactions, no. 8 (1988): 2065. http://dx.doi.org/10.1039/dt9880002065.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Wang, Sue-Lein. "Mesoporous Metal Phosphites with 3D Crystalline Frameworks." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1119. http://dx.doi.org/10.1107/s2053273314088809.

Full text

Abstract:

The synthesis of crystalline porous solids is of great importance in the area of materials chemistry. Naturally occurring zeolites are mostly crystalline; however, they possess pores/channels that only allow small species smaller than 1 nm in diameter to pass through. One exception is the mineral cacoxenite, containing 36-membered ring (36R) channels that allow guest species of up to 1.41 nm in diameter to pass through. In the past, much effort has been devoted to the development of zeolitic materials. Even though multi-faceted design strategies were utilized, the discovery of larger inorganic channels was often accidental. Compared with amorphous mesoporous silicates that contain synthetically tunable pores, zeolitic crystalline structures lack rational synthesis routes. In general, molecular templating leads to crystalline frameworks whereas organized assemblies that are able to produce much larger pores lead to noncrystalline frameworks. Synthetic methods that generate crystallinity from both discrete and organized templates represent a viable design strategy for the development of crystalline porous inorganic frameworks spanning both the micro and the meso regimes. We show by integrating templating mechanisms for both zeolites and mesoporous silica in a single system, the channel size for gallium zincophosphites can be tuned systematically up to 64R and 72R. With apertures of 3.5 nm, the new compounds represent the first non-disordered structures for mesoporous solids. Through the use of long straight-chain alkyl monoamines as templates, three common building blocks are induced that repeatedly self assemble into two isotypic porous frameworks with the ability to increasingly enlarge channel size. The rational design of crystalline porous metal oxides is achieved for the first time. A general formula was derived to predict new members with even larger channels along with their individual space group symmetry.

APA, Harvard, Vancouver, ISO, and other styles

16

Sahlman, Mika, Mari Lundström, and Dawid Janas. "Sensing Organophosphorus Compounds with SWCNT Films." Sensors 21, no. 14 (July 19, 2021): 4915. http://dx.doi.org/10.3390/s21144915.

Full text

Abstract:

Promising electrical properties of single-walled carbon nanotubes (SWCNTs) open a spectrum of applications for this material. As the SWCNT electronic characteristics respond well to the presence of various analytes, this makes them highly sensitive sensors. In this contribution, selected organophosphorus compounds were detected by studying their impact on the electronic properties of the nanocarbon network. The goal was to untangle the n-doping mechanism behind the beneficial effect of organic phosphine derivatives on the electrical conductivity of SWCNT networks. The highest sensitivity was obtained in the case of the application of 1,6-Bis(diphenylphoshpino)hexane. Consequently, free-standing SWCNT films experienced a four-fold improvement to the electrical conductivity from 272 ± 21 to 1010 ± 44 S/cm and an order of magnitude increase in the power factor. This was ascribed to the beneficial action of electron-rich phenyl moieties linked with a long alkyl chain, making the dopant interact well with SWCNTs.

APA, Harvard, Vancouver, ISO, and other styles

17

Barratt, David S., George A. Gott, and Charles A. McAuliffe. "The coordination of small molecules by manganese(II) phosphine complexes. Part 12. The synthesis of some tetrahydrofuran/long chain tertiary phosphine complexes of manganese(II) halides, MnX2(phosphine)(THF), and their reaction with molecular oxygen." Inorganica Chimica Acta 145, no. 2 (May 1988): 289–98. http://dx.doi.org/10.1016/s0020-1693(00)83972-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Zhao, Yuanjiang, Yanli Liu, Jianzhang Wei, Haiyan Fu, Xueli Zheng, Maolin Yuan, Ruixiang Li, and Hua Chen. "Nonaqueous Biphasic Hydroformylation of Long Chain Alkenes Catalyzed by Water Soluble Phosphine Rhodium Catalyst with Polyethylene Glycol Instead of Water." Catalysis Letters 148, no. 1 (November 24, 2017): 438–42. http://dx.doi.org/10.1007/s10562-017-2247-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Ganguly, Sanjoy, and D. Max Roundhill. "Conversion of long-chain terminal alcohols and secondary amines into tertiary amines using ruthenium(II) tertiary phosphine complexes as homogeneous catalysts." Polyhedron 9, no. 20 (January 1990): 2517–26. http://dx.doi.org/10.1016/s0277-5387(00)86787-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Guenther, J., J. Reibenspies, and J. Blümel. "Synthesis and characterization of tridentate phosphine ligands incorporating long methylene chains and ethoxysilane groups for immobilizing molecular rhodium catalysts." Molecular Catalysis 479 (December 2019): 110629. http://dx.doi.org/10.1016/j.mcat.2019.110629.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Yi, Jiwei, Jiangui Zhao, Songbai Tang, Chunji Yang, Haiyan Fu, Xueli Zheng, Hua Chen, Maolin Yuan, and Ruixiang Li. "A novel biphasic and recyclable system based on formamide for the hydroformylation of long-chain alkenes with water-soluble phosphine rhodium catalyst." Molecular Catalysis 505 (April 2021): 111502. http://dx.doi.org/10.1016/j.mcat.2021.111502.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Chauhan, Bhanu P. S., Ramani Thekkathu, Leon Prasanth K, Manik Mandal, and Kenrick Lewis. "Long-chain silanes as reducing agents part 1: a facile, efficient and selective route to amine and phosphine-stabilized active Pd-nanoparticles." Applied Organometallic Chemistry 24, no. 3 (March 2010): 222–28. http://dx.doi.org/10.1002/aoc.1597.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Lane, Joseph R., and Graham C. Saunders. "Theoretical Study of the Structures of 4-(2,3,5,6-Tetrafluoropyridyl)Diphenylphosphine Oxide and Tris(Pentafluorophenyl)Phosphine Oxide: Why Does the Crystal Structure of (Tetrafluoropyridyl)Diphenylphosphine Oxide Have Two Different P=O Bond Lengths?" Molecules 25, no. 12 (June 16, 2020): 2778. http://dx.doi.org/10.3390/molecules25122778.

Full text

Abstract:

The crystal structure of 4-(2,3,5,6-tetrafluoropyridyl)diphenylphosphine oxide (1) contains two independent molecules in the asymmetric unit. Although the molecules are virtually identical in all other aspects, the P=O bond distances differ by ca. 0.02 Å. In contrast, although tris(pentafluorophenyl)phosphine oxide (2) has a similar crystal structure, the P=O bond distances of the two independent molecules are identical. To investigate the reason for the difference, a density functional theory study was undertaken. Both structures comprise chains of molecules. The attraction between molecules of 1, which comprises lone pair–π, weak hydrogen bonding and C–H∙∙∙arene interactions, has energies of 70 and 71 kJ mol−1. The attraction between molecules of 2 comprises two lone pair–π interactions, and has energies of 99 and 100 kJ mol−1. There is weak hydrogen bonding between molecules of adjacent chains involving the oxygen atom of 1. For one molecule, this interaction is with a symmetry independent molecule, whereas for the other, it also occurs with a symmetry related molecule. This provides a reason for the difference in P=O distance. This interaction is not possible for 2, and so there is no difference between the P=O distances of 2.

APA, Harvard, Vancouver, ISO, and other styles

24

GANGULY, S., and D. M. ROUNDHILL. "ChemInform Abstract: Conversion of Long-Chain Terminal Alcohols and Secondary Amines into Tertiary Amines Using Ruthenium(II) Tertiary Phosphine Complexes as Homogeneous Catalysts." ChemInform 22, no. 8 (August 23, 2010): no. http://dx.doi.org/10.1002/chin.199108127.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Nikitin, Evgeny, Georgy Shumatbaev, Dmitriy Terenzhev, Kirill Sinyashin, and Kamila Kazimova. "New α-Aminophosphonates as Corrosion Inhibitors for Oil and Gas Pipelines Protection." Civil Engineering Journal 5, no. 4 (April 27, 2019): 963–70. http://dx.doi.org/10.28991/cej-2019-03091303.

Full text

Abstract:

The problem of corrosion of metal equipment is one of the most actual problems in oil industry. One of the methods to solve this problem is the development of new low-toxic, accessible and effective corrosion inhibitors. For this purpose, we carried out the synthesis of the new α-aminophosphonates based on syntanyl phosphites, formalin and diethanolamine according to the Kabachnik-Fields reaction. The resulting products are characterized by 1H, 31P, 13C NMR, IR and mass spectroscopy methods. The obtained compounds contain a long radical chain of industrial (poly)ethoxylated alcohol residue with different length of the hydroxyethyl fragment, as well as an active center containing O-P-C-N fragment, which impart them inhibitory properties toward corrosion processes. The anticorrosive activity of the new aminophosphonates was studied by gravimetric analysis method. In the article the effect of concentration, time and degree of ethoxylation of the hydrocarbon radical in alpha-aminophosphonates on the protective effect of inhibitors was studies. It was shown that the obtained aminophosphonates exhibit high values of the protective effect of steel in a highly mineralized medium containing 250 g/m3 СО2 and 200 g/m3 Н2S. The high value of the protective effect (82-85 %) at inhibitor concentration of 25 mg/l was found. The maximum protective effect at 50 mg/ml dosage of the inhibitor is 94.3 %, while there is a decrease of the corrosion rate (less than 0.04 mm/year).

APA, Harvard, Vancouver, ISO, and other styles

26

Micheel, Mathias, Bei Liu, and Maria Wächtler. "Influence of Surface Ligands on Charge-Carrier Trapping and Relaxation in Water-Soluble CdSe@CdS Nanorods." Catalysts 10, no. 10 (October 3, 2020): 1143. http://dx.doi.org/10.3390/catal10101143.

Full text

Abstract:

In this study, the impact of the type of ligand at the surface of colloidal CdSe@CdS dot-in-rod nanostructures on the basic exciton relaxation and charge localization processes is closely examined. These systems have been introduced into the field of artificial photosynthesis as potent photosensitizers in assemblies for light driven hydrogen generation. Following photoinduced exciton generation, electrons can be transferred to catalytic reaction centers while holes localize into the CdSe seed, which can prevent charge recombination and lead to the formation of long-lived charge separation in assemblies containing catalytic reaction centers. These processes are in competition with trapping processes of charges at surface defect sites. The density and type of surface defects strongly depend on the type of ligand used. Here we report on a systematic steady-state and time-resolved spectroscopic investigation of the impact of the type of anchoring group (phosphine oxide, thiols, dithiols, amines) and the bulkiness of the ligand (alkyl chains vs. poly(ethylene glycol) (PEG)) to unravel trapping pathways and localization efficiencies. We show that the introduction of the widely used thiol ligands leads to an increase of hole traps at the surface compared to trioctylphosphine oxide (TOPO) capped rods, which prevent hole localization in the CdSe core. On the other hand, steric restrictions, e.g., in dithiolates or with bulky side chains (PEG), decrease the surface coverage, and increase the density of electron trap states, impacting the recombination dynamics at the ns timescale. The amines in poly(ethylene imine) (PEI) on the other hand can saturate and remove surface traps to a wide extent. Implications for catalysis are discussed.

APA, Harvard, Vancouver, ISO, and other styles

27

Amon-Armah, Frederick, Solomon Sefa Oduro, Eric Kofi Doe, Moses Asani, Daniel Nyadanu, and Sampson Konlan. "Supply-Side Practices and Constraints of the Kola Nut (Cola nitida (Vent) Schott. and Endl.) Value Chain in Ghana: A Descriptive Evidence." International Journal of Agronomy 2021 (May 30, 2021): 1–16. http://dx.doi.org/10.1155/2021/9942699.

Full text

Abstract:

The use of kola nut, including natural or alternative medicinal sources, has inevitably created an increased global market demand in excess of its production and provides great prospects for the growth of the kola nut industry in producing countries like Ghana. Nonetheless, there is a great dearth of information on Ghana’s kola nut supply-side practices and constraints that can provide a basis for the development of the industry. This study fills the research gap by describing the practices and constraints of farmers, processors, and marketers of kola nut in Ghana. Using a survey methodology, results showed that nearly all (99.5%) farmers interviewed had not received any extension training on agronomic practices. Low market price of nuts (61.5%) and pests and diseases (60.4%) were the most reported constraints to kola nut production. Chiefs among motivating factors for cultivating kola nut were alternative livelihood support (58%). Some processors (28.6%) who rinsed nuts after depulping used a solution of Akate Master (bifenthrin) and others (51.0%) used fumigation tablets (aluminium phosphide) (91.0%) for storing the nuts. However, these chemicals may be dangerous to the health of consumers in the long run. The low selling price of kola nuts was perceived to be the most (74.8%) constraint to kola nut processing and marketing. Respondents noted that the red nuts were preferred for their durability during transportation and longer shelf life, while the white nuts were preferred for their taste. The results suggest the need for further agronomic, postharvest handling, preservation, and storage, as well as breeding research to provide recommendations to farmers and processors. To overcome some marketing challenges, there is a need for policy support to standardize pricing and grading systems for the mutual benefit of all the stakeholders.

APA, Harvard, Vancouver, ISO, and other styles

28

Lee, Jongwon, Jae Yong Lee, Jonghyun Song, Gapseop Sim, Hyoungho Ko, and Seong Ho Kong. "Implementation of Flip-Chip Microbump Bonding between InP and SiC Substrates for Millimeter-Wave Applications." Micromachines 13, no. 7 (July 5, 2022): 1072. http://dx.doi.org/10.3390/mi13071072.

Full text

Abstract:

Flip-chip microbump (μ-bump) bonding technology between indium phosphide (InP) and silicon carbide (SiC) substrates for a millimeter-wave (mmW) wireless communication application is demonstrated. The proposed process of flip-chip μ-bump bonding to achieve high-yield performance utilizes a SiO2-based dielectric passivation process, a sputtering-based pad metallization process, an electroplating (EP) bump process enabling a flat-top μ-bump shape, a dicing process without the peeling of the dielectric layer, and a SnAg-to-Au solder bonding process. By using the bonding process, 10 mm long InP-to-SiC coplanar waveguide (CPW) lines with 10 daisy chains interconnected with a hundred μ-bumps are fabricated. All twelve InP-to-SiC CPW lines placed on two samples, one of which has an area of approximately 11 × 10 mm2, show uniform performance with insertion loss deviation within ±10% along with an average insertion loss of 0.25 dB/mm, while achieving return losses of more than 15 dB at a frequency of 30 GHz, which are comparable to insertion loss values of previously reported conventional CPW lines. In addition, an InP-to-SiC resonant tunneling diode device is fabricated for the first time and its DC and RF characteristics are investigated.

APA, Harvard, Vancouver, ISO, and other styles

29

Rosowsky, Andre, Hongning Fu, Niranjan Pai, John Mellors, Douglas D. Richman, and Karl Y. Hostetler. "Synthesis and in Vitro Activity of Long-Chain 5‘-O-[(Alkoxycarbonyl)phosphinyl]-3‘-azido-3‘-deoxythymidines against Wild-Type and AZT- and Foscarnet-Resistant Strains of HIV-1." Journal of Medicinal Chemistry 40, no. 16 (August 1997): 2482–90. http://dx.doi.org/10.1021/jm970172f.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Trofimov, Boris, Vladimir Kuimov, Svetlana Malysheva, Natalia Belogorlova, and Nina K. Gusarova. "Chemoselective synthesis of long-chain alkyl-Н-phosphinic acids via one-pot alkylation/oxidation of red phosphorus with alkylPEGs as recyclable micellar catalysts." Organic & Biomolecular Chemistry, 2021. http://dx.doi.org/10.1039/d1ob01470f.

Full text

Abstract:

Long-chain n-alkyl-H-phosphinic acids (Alk = C4-C18) are chemoselectively synthesized in up to 90% yield via the direct one-pot alkylation/oxidation of red phosphorus (Pn) in the multi-phase alkyl bromide/KOH/H2O/toluene system with...

APA, Harvard, Vancouver, ISO, and other styles

31

BARRATT, D. S., G. A. GOTT, and C. A. MCAULIFFE. "ChemInform Abstract: The Coordination of Small Molecules by Manganese(II) Phosphine Complexes. Part 11. The Coordination of Dioxygen by Manganese(II) Complexes Containing Long-Chain Phosphine Ligands." ChemInform 19, no. 49 (December 6, 1988). http://dx.doi.org/10.1002/chin.198849227.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

BARRATT, D. S., G. A. GOTT, and C. A. MCAULIFFE. "ChemInform Abstract: The Coordination of Small Molecules by Manganese(II) Phosphine Complexes. Part 12. The Synthesis of Some Tetrahydrofuran/Long Chain Tertiary Phosphine Complexes of Manganese(II) Halides, MnX2." ChemInform 19, no. 34 (August 23, 1988). http://dx.doi.org/10.1002/chin.198834257.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

CASPAR, J. V. "ChemInform Abstract: Long-Lived Reactive Excited States of Zero-Valent Phosphine, Phosphite, and Arsine Complexes of Nickel, Palladium, and Platinum." Chemischer Informationsdienst 17, no. 10 (March 11, 1986). http://dx.doi.org/10.1002/chin.198610346.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Rawls, Brian, Jeremy Cunningham, John E. Bender, Richard J. Staples, and Shannon M. Biros. "Crystal structures of (Z)-(ethene-1,2-diyl)bis(diphenylphosphine sulfide) and its complex with Pt^II dichloride." Acta Crystallographica Section E Crystallographic Communications 79, no. 1 (January 1, 2023). http://dx.doi.org/10.1107/s2056989022011847.

Full text

Abstract:

The crystal structures of (Z)-(ethene-1,2-diyl)bis(diphenylphosphine sulfide), C26H22P2S2 (I), along with its complex with PtII dichloride, dichlorido[(Z)-(ethene-1,2-diyl)bis(diphenylphosphine sulfide)-κ2 S,S′]platinum(II), [PtCl2(C26H22P2S2)] (II), are described here. Compound I features P=S bond lengths of 1.9571 (15) and 1.9529 (15) Å, with a torsion angle of 166.24 (7)° between the two phosphine sulfide groups. The crystal of compound I features both intramolecular C—H...S hydrogen bonds and π–π interactions. Molecules of compound I are held together with intermolecular π–π and C—H...π interactions to form chains that run parallel to the z-axis. The intermolecular C—H...π interaction has a H...Cg distance of 2.63 Å, a D...Cg distance of 3.573 (5) Å and a D—H...Cg angle of 171° (where Cg refers to the centroid of one of the phenyl rings). These chains are linked by relatively long C—H...S hydrogen bonds with D...A distances of 3.367 (4) and 3.394 (4) Å with D—H...A angles of 113 and 115°. Compound II features Pt—Cl and Pt—S bond lengths of 2.3226 (19) and 2.2712 (19) Å, with a P=S bond length of 2.012 (3) Å. The PtII center adopts a square-planar geometry, with Cl—Pt—Cl and S—Pt—S bond angles of 90.34 (10) and 97.19 (10)°, respectively. Molecules of compound II are linked in the crystal by intermolecular C—H...Cl and C—H...S hydrogen bonds.

APA, Harvard, Vancouver, ISO, and other styles

35

Martín, Juan F., Paloma Liras, and Sergio Sánchez. "Modulation of Gene Expression in Actinobacteria by Translational Modification of Transcriptional Factors and Secondary Metabolite Biosynthetic Enzymes." Frontiers in Microbiology 12 (March 16, 2021). http://dx.doi.org/10.3389/fmicb.2021.630694.

Full text

Abstract:

Different types of post-translational modifications are present in bacteria that play essential roles in bacterial metabolism modulation. Nevertheless, limited information is available on these types of modifications in actinobacteria, particularly on their effects on secondary metabolite biosynthesis. Recently, phosphorylation, acetylation, or phosphopantetheneylation of transcriptional factors and key enzymes involved in secondary metabolite biosynthesis have been reported. There are two types of phosphorylations involved in the control of transcriptional factors: (1) phosphorylation of sensor kinases and transfer of the phosphate group to the receiver domain of response regulators, which alters the expression of regulator target genes. (2) Phosphorylation systems involving promiscuous serine/threonine/tyrosine kinases that modify proteins at several amino acid residues, e.g., the phosphorylation of the global nitrogen regulator GlnR. Another post-translational modification is the acetylation at the epsilon amino group of lysine residues. The protein acetylation/deacetylation controls the activity of many short and long-chain acyl-CoA synthetases, transcriptional factors, key proteins of bacterial metabolism, and enzymes for the biosynthesis of non-ribosomal peptides, desferrioxamine, streptomycin, or phosphinic acid-derived antibiotics. Acetyltransferases catalyze acetylation reactions showing different specificity for the acyl-CoA donor. Although it functions as acetyltransferase, there are examples of malonylation, crotonylation, succinylation, or in a few cases acylation activities using bulky acyl-CoA derivatives. Substrates activation by nucleoside triphosphates is one of the central reactions inhibited by lysine acetyltransferases. Phosphorylation/dephosphorylation or acylation/deacylation reactions on global regulators like PhoP, GlnR, AfsR, and the carbon catabolite regulator glucokinase strongly affects the expression of genes controlled by these regulators. Finally, a different type of post-translational protein modification is the phosphopantetheinylation, catalized by phosphopantetheinyl transferases (PPTases). This reaction is essential to modify those enzymes requiring phosphopantetheine groups like non-ribosomal peptide synthetases, polyketide synthases, and fatty acid synthases. Up to five PPTases are present in S. tsukubaensis and S. avermitilis. Different PPTases modify substrate proteins in the PCP or ACP domains of tacrolimus biosynthetic enzymes. Directed mutations of genes encoding enzymes involved in the post-translational modification is a promising tool to enhance the production of bioactive metabolites.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!