75,720 research outputs found
C–H Amination Mediated by Cobalt Organoazide Adducts and the Corresponding Cobalt Nitrenoid Intermediates
No full textTreatment of ((Ar)L)CoBr ((Ar)L = 5-mesityl-1,9-(2,4,6-Ph(3)C(6)H(2))dipyrrin) with a stoichiometric amount of 1-azido-4-(tert-butyl)benzene N(3)(C(6)H(4)-p-(t)Bu) furnished the corresponding four-coordinate organoazide-bound complex ((Ar)L)CoBr(N(3)(C(6)H(4)-p-(t)Bu)). Spectroscopic and structural characterization of the complex indicated redox innocent ligation of the organoazide. Slow expulsion of dinitrogen (N(2)) was observed at room temperature to afford a ligand functionalized product via a [3+2] annulation, which can be mediated by a high-valent nitrene intermediate such as a Co(III) iminyl ((Ar)L)CoBr((·)N(C(6)H(4)-p-(t)Bu)) or Co(IV) imido ((Ar)L)CoBr(N(C(6)H(4)-p-(t)Bu)) complex. The presence of the proposed intermediate and its viability as a nitrene group transfer reagent are supported by intermolecular C–H amination and aziridination reactivities. Unlike ((Ar)L)CoBr(N(3)(C(6)H(4)-p-(t)Bu)), a series of alkyl azide-bound Co(II) analogues expel N(2) only above 60 °C, affording paramagnetic intermediates that convert to the corresponding Co-imine complexes via α–H–atom abstraction. The corresponding N(2)-released structures were observed via single-crystal-to-crystal transformation, suggesting formation of a Co-nitrenoid intermediate in solid-state. Alternatively, the alkyl azide-bound congeners supported by a more sterically accessible dipyrrinato scaffold (tBu)L ((tBu)L = 5-mesityl-(1,9-di-tert-butyl)dipyrrin) facilitate intramolecular 1,3-dipolar cycloaddition as well as C–H amination to furnish 1,2,3-dihydrotriazole and substituted pyrrolidine products, respectively. For the C–H amination, we observe that the temperature required for azide activation varies depending on the presence of weak C–H bonds, suggesting that the alkyl azide adducts serve as viable species for C–H amination when the C–H bonds are (1) proximal to the azide moiety and (2) sufficiently weak to be activated
Onycholabis pedulangulus Liang and Imura 2003
No full textOnycholabis pedulangulus Liang and Imura, 2003:688 (China, Vietnam, Laos). Specimens Examined. Total 83 specimens; for 73 types, refer to Liang and Imura (2003); additional specimens: CHINA: Yunnan Province, 5 males and 5 females (IOZ, CAS), ‘‘ China, Yunnan Province, Tengchong, Wuhe Town, Longjiangqiao, riverside, 24853956.00N, 98840936.10E’’/‘‘ 1,215 m, 2003.10.28, Liang H. B., Shi X. C. coll. Institute of Zool., CAS and California Acad. Sciences’ ’. Description. See Liang and Imura (2003). Distribution. Known from Laos, Vietnam, and China. Remarks. Adults of this species have been found on river banks and on the walls of roadside drainage ditches.Published as part of Liang, Hongbin & Kavanaugh, David H., 2005, A Review of Genus Onycholabis Bates (Coleoptera: Carabidae: Platynini), with Description of a New Species from Western Yunnan, China, pp. 507-520 in The Coleopterists Bulletin 59 (4) on page 512, DOI: 10.1649/837.
Onycholabis stenothorax Liang and Kavanaugh, new species
No full textOnycholabis stenothorax Liang and Kavanaugh, new species (Figs. 6–11) Types. Holotype, a male, in IOZ, labelled: ‘‘ China, Yunnan Province, Tengchong, Qushi Town, Xiangyangqiao, riverside, 25812938.40N, 98834949.40E’’/‘‘ 1,515 m, 2003.10.23, night, Liang H. B., Shi X. C. Coll., Institute of Zool., CAS & California Acad. Sciences’ ’/‘‘ HOLOTYPE Onycholabis stenothorax Liang & Kavanaugh’’ [red label]. Paratypes: 6 males and 1 female, same data as holotype; 2 males and 2 females, ‘‘ China, Yunnan Province, Longling, Zhen’an Town, Bangbie, along a stream, 24848947.40N, 98849959.10E’’/‘‘ 1,540 m, 2003.10.30, day, Liang H. B., Shi X. C. Coll., Institute of Zool., CAS & California Acad. Sciences’ ’; 2 females, ‘‘ China, Yunnan Province, Tengchong, Wuhe Town, Zhengding, stream side, 24850946.20N, 98845914.50E’’/‘‘ 1,985 m, 2003.10.29, day, Liang H. B., Shi X. C. Coll., Institute of Zool., CAS & California Acad.Sciences’ ’. Among the 13 paratypes, five specimens are deposited in CAS, six in IOZ, and two in KIZ. Type Locality. Qushi, Tengchong County, Baoshan Prefecture, Yunnan Province, China. Diagnosis. This new species seems to be most closely related to O. melitopus Bates and O. nakanei Kasahara, based on chaetotaxy of the pronotum; but adults are readily distinguishable from those of O. melitopus by the rounded elytral apices at the sutural angles, and from those of O. nakanei by the narrow pronotum and reduced number (2 in males and 6 in females) of marginal setae on the sixth visible sternum. Description. Body length 10.7–12.0 mm (including mandibles). Width: 3.4–3.9 mm. Body black, shiny dorsally; mandibles, labrum and mentum red-brown; antennae, palpi and legs light brown. Head with large and markedly prominent eyes and markedly constricted neck; vertex slightly convex above with surface very smooth and shiny, microsculpture partly and sparsely visible and formed of isodiametric meshes; frontal furrows deeply concave, almost parallel anteriorly and slightly divergent posteriorly, surface laterad of frontal furrows longitudinally rugose; anterior supraorbital seta inserted anterior to mid-eye level, posterior supraorbital seta inserted slightly anterior to post-eye level; mandibles long, slender, gently curved inwards and gradually tapered towards tips [which are not as sharply pointed as in other species]; terminal maxillary palpomeres slender, almost as long as penultimate palpomeres, cylindrical in median portion and truncate at apices; terminal labial palpomere shorter than penultimate; penultimate palpomeres bisetose; median tooth of mentum bifid, with each apex sharply pointed; submentum quadrisetose; antennae filiform, extended to middle of elytra; relative lengths of scape and antennomeres II–VI as follows: 1.0: 0.44: 1.65: 1.51: 1.14: 1.14. Pronotum cordate, longer than wide, widest at about apical one-third, narrower than head, PW/ HW ¼ 0.89 (0.85–0.92), PW/PL ¼ 1.05 (0.98–1.10), PW/PAW ¼ 1.34 (1.29–1.39), PW/PBW ¼ 1.47 (1.41–1.55); apical margin widely and rather shallowly emarginate throughout; front angles rounded, obtuse at tips; lateral margins finely reflexed, arcuate before widest parts, rather gradually convergent to basal one-sixth, then slightly sinuate anterior to rectangular, pointed hind angles; 1 pair of marginal setae inserted slightly before widest part; basal margin distinctly bisinuate and unbordered throughout; disc moderately convex above, with surface smooth, except for sparse and scattered large punctures along basal and lateral portions, microsculpture evident as transverse meshes; median longitudinal furrow narrow but distinctly impressed throughout, basal foveae deep. Elytra subovate, moderately convex above, widest slightly behind middle, much wider than pronotum, EL/EW ¼ 1.73 (1.64–1.77), EW/PW ¼ 1.89 (1.83–1.92); basal margination short and slightly curved; basal margins wide, oblique and extended to humeri, which are distinct but rounded; lateral margins almost parallel-sided in basal portions, moderately convergent towards apices, slightly but distinctly produced just before apices which are conjointly rounded; scutellar striole long, extended onto interval I and punctate; striae between intervals deeply impressed, with regularly spaced punctures except indistinctly punctate in apical portion; intervals smooth, with microsculpture evident as transverse meshes, slightly convex in apical half and flatter towards apex; interval III with 1 setiferous pore puncture at basal one-fifth near stria III and a second just behind middle and near stria II (2 specimens with 3 pore punctures on one elytron). Prosternum, lateral portions of metaternum and pro- and metepisterna coarsely punctate. Sixth visible sternum with 2 marginal seta in male, 6 in female. Legs long and slender; protarsomeres I–III slightly dilated in male, with two rows of adhesive hairs on ventral side; tarsomere IV bilobed apically. Male genitalia with aedeagus long and slender, slightly arcuate at basal one-third in lateral view, then almost straight toward rounded apex (Fig. 7); in dorsal view, apical lamella slightly tapered towards apex, nearly as long as wide (Fig. 8); left paramere broadly subovate and rounded at apex (Fig. 9); right paramere small and narrow, with rounded apex (Fig. 10). Female reproductive tract as in Figure 11; basal gonocoxite I with apical fringe of 13 setae; apical gonocoxite II with 7 dorsolateral and 1 dorsomedial ensiform setae; bursa copulatrix without microtrichia, spermatheca slightly arcuate, spermathecal gland with spherical apex. Distribution. Presently known from Tengchong, Baoshan and Longling counties, on both western and eastern slopes of the Gaoligong Mountains in western Yunnan Province, China. Etymology. This new species is named for its narrow pronotum.Published as part of Liang, Hongbin & Kavanaugh, David H., 2005, A Review of Genus Onycholabis Bates (Coleoptera: Carabidae: Platynini), with Description of a New Species from Western Yunnan, China, pp. 507-520 in The Coleopterists Bulletin 59 (4) on pages 514-516, DOI: 10.1649/837.
Mellin-Transform-Based Performance Analysis of FFH -ary FSK Using Product Combining for Combatting Partial-Band Noise Jamming
No full textLetter from C. H. Gensler, Havasupai Agency to Carl Hayden
No full textLetter from C. H. Gensler expressing concern on behalf of the Havasupai Tribe regarding the proposed park boundaries
Citations of the author H C Rajpoot
No full textThe list of the articles, research papers, theses, and book chapters globally citing the author H. C. Rajpoot</p
Letter from Carl Hayden to C. H. Gensler
No full textLetter from Carl Hayden to C. H. Gensler informing him of the proposed Grand Canyon National Park bill
Letter from C. H. Gensler, Havasupai Agency to Carl Hayden
No full textLetter from C. H. Gensler to Carl Hayden asking for a meeting in regards to the Havasupai pasture land in light of the national park bill
Catalyst‐Guided C=Het Hydroarylations by Manganese‐Catalyzed Additive‐Free C−H Activation
No full textExpedient hydroarylations of C=Het bonds (Het = heteroatom) were accomplished by user-friendly organometallic C-H activation in a positional-selective manner. The broadly applicable C-H functionalization platform enabled the step-economical transformation of aldehydes, ketones, and imines under additive-free reaction conditions. In contrast to palladium, rhodium, ruthenium, rhenium, iridium, nickel, and cobalt catalysis, solely manganese(I) complexes outcompeted the innate substrate control, clearly highlighting the unique power of manganese(I) C-H activation catalysis
Chrysosporium kaiyangense Y. F. Han, W. H. Chen, J. D. Liang & Z. Q. Liang 2022, sp. nov.
No full textChrysosporium kaiyangense Y.F. Han, W.H. Chen, J.D. Liang & Z.Q. Liang, sp. nov. (Fig. 7) Mycobank No.: MB 838868 Type: — CHINA. Guizhou Province: Kaiyang City, N27°06′, E107°09′, from soil, August 2017, Yanfeng Han, holotype GZAC. EB0702 M; ex-type culture GZU. EB0702 M. Colonies on PDA attaining about 35 mm diam. at 26 °C after 14 days, raised in the center, felty, white, margin sparsely villiform; reverse yellowish. Hyphae septate, smooth, hyaline, 2.0–3.0 μm thick. Racquet hyphae absent. Terminal and lateral conidia hyaline, smooth, arising from aerial hyphae directly or on short protrusions, 1- or 3- celled, solitary, obovoid, 2.0–3.5 × 1.0–2.5 μm, or cylindrical to clavate, 4.0–10.5 × 2.0–3.0 μm, with truncate base, basal scars 1.5–2.0 μm; intercalary conidia absent. Chlamydospores absent. Etymology: —Referring to the region from which the fungus was isolated. Known distribution: —Kaiyang city, Guizhou Province, China.Published as part of Han, Yan-Feng, Ge, Wei, Zhang, Zhi-Yuan, Liang, Jian-Dong, Chen, Wan-Hao, Huang, Jian- Zhong & Liang, Zong-Qi, 2022, Morphological and phylogenetic characterisations reveal nine new species of Chrysosporium (Onygenaceae, Onygenales) in China, pp. 1-16 in Phytotaxa 539 (1) on pages 9-10, DOI: 10.11646/phytotaxa.539.1.1, http://zenodo.org/record/634590
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