Planarized Triarylboranes: Stabilization by Structural Constraint and Their Plane-to-Bowl Conversion

Triphenylborane and 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene, constrained to a planar arrangement with methylene tethers, were synthesized by intramolecular multi-fold Friedel–Crafts cyclization. These compounds were stable toward air, water, and amines, despite the absence of steric protection in the vertical direction with respect to the B atoms, and showed characteristic structural, electronic, and photophysical properties. In addition, upon treatment with a fluoride ion, these compounds underwent a plane-to-bowl conversion in a controlled manner

Planarized Triarylboranes: Stabilization by Structural Constraint and Their Plane-to-Bowl Conversion

Triphenylborane and 9,10-diphenyl-9,10-dihydro-9,10-diboraanthracene, constrained to a planar arrangement with methylene tethers, were synthesized by intramolecular multi-fold Friedel–Crafts cyclization. These compounds were stable toward air, water, and amines, despite the absence of steric protection in the vertical direction with respect to the B atoms, and showed characteristic structural, electronic, and photophysical properties. In addition, upon treatment with a fluoride ion, these compounds underwent a plane-to-bowl conversion in a controlled manner

Correlation coefficients among parameters in fibers on FP1 and FP3 of two cultivars during 2010–2011.

<p>The coefficient between UHM and <i>CEL</i>max (A), ST and <i>CEL</i>max (B), MIC and <i>CEL</i>max (C), UHM and <i>Tr</i> (D), ST and <i>Tr</i> (E), and MIC and <i>Tr</i> (F) in fibers on FP1 and FP3 of two cultivars. UHML-fiber upper-half mean length, MIC-micronaire value, ST-fiber strength, <i>CEL</i>max-maximum cellulose content, <i>Tr</i>-sucrose transformation rate. * and **, significant differences at <i>P</i> = 0.01 and <i>P</i> = 0.05 probability levels, respectively. n = 12, <i>R</i>_0.05 = 0.576, <i>R</i>_0.01 = 0.707.</p

Correlation coefficients between cellulose content and sucrose transformation rate in fibers during 2010–2011.

<p>The coefficient between <i>CEL</i>max and <i>Tr</i> in fibers on FP1 and FP3 of Kemian 1 (A), <i>CEL</i>max and <i>Tr</i> in fibers on FP1 and FP3 of Sumian 15 (B). <i>CEL</i>max-maximum cellulose content, <i>Tr-</i>sucrose transformation rate. * and **, significant differences at <i>P</i> = 0.01 and <i>P</i> = 0.05 probability levels, respectively. n = 12, <i>R</i>_0.05 = 0.576, <i>R</i>_0.01 = 0.707.</p

Mean daily temperature, mean daily maximum temperature, mean daily minimum temperature, mean diurnal temperature difference, total solar radiation and cumulative photo-thermal index during cotton fiber development period from flowering date to boll opening date on FP1 and FP3 of two cultivars during 2010–2011.

a<p>MDT, mean daily temperature.</p>b<p>MDTmax, mean daily maximum temperature.</p>c<p>MDTmin, mean daily minimum temperature.</p>d<p>MDTdif, mean diurnal temperature difference.</p>e<p>MDSR, mean daily solar radiation.</p>f<p><i>PTI</i>, cumulative photo-thermal index during cotton fiber development period.</p>g<p>Weather data were provided by Nanjing Weather Station, which was located nearby the experimental site.</p>h<p>CV, coefficient of variation.</p

Changes of enzymes activities in fibers on FP1 and FP3 of two cultivars during 2010–2011.

<p>The activities of SuSy (A), AI (B) and SPS (C) in fibers on FP1 and FP3 of two cultivars. SuSy-sucrose sythase, AI-acid invatse and SPS-sucrose phosphate sythase. Values followed by a different letter between fruiting positions are significantly different at <i>P</i> = 0.05 probability level. Each value represents the mean of three replications.</p

Fiber properties of field-grown cotton on FP1 and FP3 of two cultivars during 2010–2011.

a<p>UHML, fiber upper-half mean length.</p>b<p>UI, uniformity index.</p>c<p>MIC, micronaire value.</p>d<p>EL, elongation percentage.</p>e<p>ST, fiber strength.</p>f<p>Values followed by a different letter between fruiting positions are significantly different at <i>P</i> = 0.05 probability level. Each value represents the mean of three replications.</p>g<p>CV, coefficient of variation.</p>h<p>* and ** indicate significant differences at P≤0.05 and 0.01 probability levels, respectively. ns, not significant (P≥0.05).</p

Comparisons of effect indices and coefficients of variations on the activities of sucrose metabolism enzymes in cotton fibers on FP1 and FP3 of two cultivars during 2010–2011.

a<p>DPA, day post anthesis.</p>b<p>EI, the effect indices values, which were calculated as EI_X =  (X_FP1-X_FP3)/X_FP1^*100%. If EI>0, it is a decrease variation in FP3 compared with FP1. If EI<0, it is an increase variation in FP3 compared with FP1.</p>c<p>CV, coefficient of variation (%).</p

Cellulose content, sucrose content and sucrose transformation rate in cotton fibers on FP1 and FP3 of two cultivars during 2010–2011.

a<p><i>Tr</i>, sucrose transformation rate.</p>b<p>DPA, days post anthesis.</p>c<p>Values followed by a different letter between fruiting positions are significantly different at <i>P</i> = 0.05 probability level. Each value represents the mean of three replications.</p

Correlation coefficient of environmental factors during cotton fiber development period with maximum/minimum sucrose content and sucrose transformation rate in cotton fibers on FP1 and FP3 of two cultivars during 2010–2011.

a<p><i>SUC</i>max, maximum sucrose content.</p>b<p><i>SUC</i>min, minimum sucrose content.</p>c<p><i>Tr</i>, sucrose transformation rate.</p>d<p>n =  8, <i>R</i>_0.05 = 0.707, <i>R</i>_0.01 = 0.834. *, significant differences at <i>P</i> = 0.05 probability level.</p