Quantitative-Analysis of the Distribution of Organelles in Tobacco Pollen Tubes - Implications for Exocytosis and Endocytosis

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Bipyridine Adducts of Molybdenum Imido Alkylidene and Imido Alkylidyne Complexes

Seven bipyridine adducts of molybdenum imido alkylidene bispyrrolide complexes of the type Mo­(NR)­(CHCMe₂R′)­(Pyr)₂(bipy) (<b>1a</b>–<b>1g</b>; R = 2,6-<i>i</i>-Pr₂C₆H₃ (Ar), adamantyl (Ad), 2,6-Me₂C₆H₃ (Ar′), 2-<i>i</i>-PrC₆H₄ (Ar^<i>i</i>Pr), 2-ClC₆H₄ (Ar^Cl), 2-<i>t</i>-BuC₆H₄ (Ar^<i>t</i>Bu), and 2-MesitylC₆H₄ (Ar^M), respectively; R′ = Me, Ph) have been prepared using three different methods. Up to three isomers of the adducts are observed that are proposed to be the <i>trans</i>- and two possible <i>cis</i>-pyrrolide isomers of <i>syn</i>-alkylidenes. Sonication of a mixture containing <b>1a</b>–<b>1g</b>, HMTOH (2,6-dimesitylphenol), and ZnCl₂(dioxane) led to the formation of MAP species of the type Mo­(NR)­(CHCMe₂R′)­(Pyr)­(OHMT) (<b>3a</b>–<b>3g</b>). DCMNBD (2,3-dicarbomethoxynorbornadiene) is polymerized employing <b>3a</b>–<b>3g</b> as initiators to yield >98% <i>cis</i>,<i>syndiotactic</i> poly­(DCMNBD). Attempts to prepare bipy adducts of bisdimethylpyrrolide complexes led to the formation of imido alkylidyne complexes of the type Mo­(NR)­(CCMe₂R′)­(Me₂Pyr)­(bipy) (Me₂Pyr = 2,5-dimethylpyrrolide; <b>4a</b>–<b>4g</b>) through a ligand-induced migration of an alkylidene α proton to a dimethylpyrrolide ligand. X-ray structures of Mo­(NAr)­(CHCMe₂Ph)­(Pyr)₂(bipy) (<b>1a</b>), Mo­(NAr^<i>i</i>Pr)­(CHCMe₂Ph)­(Pyr)­(OHMT) (<b>3d</b>), Mo­(NAr)­(CCMe₂Ph)­(Me₂Pyr)­(bipy) (<b>4a</b>), the NAr′ analog of <b>4a</b> (<b>4c</b>), and Mo­(NAr^T)­(CCMe₃)­(Me₂Pyr)­(bipy) (Ar^T = 2-(2,4,6-<i>i</i>-Pr₃C₆H₂)­C₆H₄; <b>4g</b>) showed normal bond lengths and angles

Bipyridine Adducts of Molybdenum Imido Alkylidene and Imido Alkylidyne Complexes

Seven bipyridine adducts of molybdenum imido alkylidene bispyrrolide complexes of the type Mo(NR)(CHCMe[subscript 2]R′)(Pyr)[subscript 2](bipy) (1a–1g; R = 2,6-i-Pr[subscript 2]C[subscript 6]H[subscript 3] (Ar), adamantyl (Ad), 2,6-Me[subscript 2]C[subscript 6]H[subscript 3] (Ar′), 2-i-PrC[subscript 6]H[subscript 4] (Ar[superscript iPr]), 2-ClC[subscript 6]H[subscript 4] (Ar[superscript Cl]), 2-t-BuC[subscript 6]H[subscript 4] (Ar[superscript tBu]), and 2-MesitylC[subscript 6]H[subscript 4] (Ar[superscript M]), respectively; R′ = Me, Ph) have been prepared using three different methods. Up to three isomers of the adducts are observed that are proposed to be the trans- and two possible cis-pyrrolide isomers of syn-alkylidenes. Sonication of a mixture containing 1a–1g, HMTOH (2,6-dimesitylphenol), and ZnCl[subscript 2](dioxane) led to the formation of MAP species of the type Mo(NR)(CHCMe[subscript 2]R′)(Pyr)(OHMT) (3a–3g). DCMNBD (2,3-dicarbomethoxynorbornadiene) is polymerized employing 3a–3g as initiators to yield >98% cis,syndiotactic poly(DCMNBD). Attempts to prepare bipy adducts of bisdimethylpyrrolide complexes led to the formation of imido alkylidyne complexes of the type Mo(NR)(CCMe[subscript 2]R′)(Me[subscript 2]Pyr)(bipy) (Me[subscript 2]Pyr = 2,5-dimethylpyrrolide; 4a–4g) through a ligand-induced migration of an alkylidene α proton to a dimethylpyrrolide ligand. X-ray structures of Mo(NAr)(CHCMe[subscript 2]Ph)(Pyr)[subscript 2](bipy) (1a), Mo(NAr[superscript iPr])(CHCMe[subscript 2]Ph)(Pyr)(OHMT) (3d), Mo(NAr)(CCMe[subscript 2]Ph)(Me[subscript 2]Pyr)(bipy) (4a), the NAr′ analog of 4a (4c), and Mo(NAr[superscript T])(CCMe[subscript 3])(Me[subscript 2]Pyr)(bipy) (Ar[superscript T] = 2-(2,4,6-i-Pr[subscript 3]C[subscript 6]H[subscript 2])C[subscript 6]H[subscript 4]; 4g) showed normal bond lengths and angles.National Science Foundation (U.S.) (CHE-0841187)National Science Foundation (U.S.) (CHE-1111133)United States. Dept. of Energy (DE-FG02-86ER13564)National Institutes of Health (U.S.) (GM-59426