Conversion of alkynes and nitriles into organo and organonitrogenated species at group VI and VII dinitrogen-binding metal centers. Synthesis of some vinylidene and alkynyl complexes of rhenium

Summary The reactions of phenylacetylene and other alkynes [HCCCH₂OH, HCC(CH₂)₂OH, HCCCH₂CMe ₂CH₂COCH₃, HCCSiMe ₃ andMeCCSiMe ₃], in the presence of acetonitrile or benzonitrile, with the following complexes have been investigated usually at room temperature:trans-[Mo(N₂)₂ L ₄] (L=PMe ₂ Ph),cis-[Mo(N₂)₂(PMePh ₂)₄],cis-[W(N₂)₂ L ₄],trans-[ReCl(N₂)L ₄],mer-[ReCl(N₂)(PPh ₃)L₃] {L=P(OMe)₃}, [ReCl₂(N₂COPh)L₃] and [(⁵-MeC₅H₄)Mn(CO)₂(NCMe)]. Cyclic trimerization was the main reaction detected for phenylacetylene (except for the Mn complex), although dimers, products of hydrogenation and species derived from alkyne/nitrile coupling were also formed in smaller amounts; for the Mo- or W-systems, the total yields were below ca. 40% relative to the metal, but the Re-systems exhibited a modest catalytic activity. The other alkynes underwent, also in low yields, mainly dimerization, cyclic or linear trimerization, apart from, to a smaller extent, coupling reactions with the nitriles or hydrogenation. The alkynyl complexes [ReCl(CCPh) {P(O) (OMe)₂}(PPh ₃)L₂] and [ReCl(CCPh) {P(O)(OMe)₂}(NCMe)₂ L] were prepared by reaction ofmer-[ReCl(N₂)(PPh ₃)L₃] withPhCCH, in the absence and in the presence of NCMe, respectively, whereas the benzonitrile/dinitrogen complex [ReCl(N₂)(CNPh)L₃] was obtained either by reaction of that N₂-complex with NCPh or by the reaction of [ReCl₂(N₂COPh)L₃] with NCPh in the presence of NaOMe. The vinylidene compoundtrans-[Re(CNMe)(C=CHPh)(dppe)₂][BF₄] (dppe=Ph ₂PCH₂CH₂PPh ₂) was formed by reaction oftrans-[ReCl(CNMe)(dppe)₂] withPhCCH, in the presence of Tl[BF₄], which did not lead to the formation of detectable amounts of any alkyne-derived organic product.

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Umsetzung von Alkinen und Nitrilen zu Organo- und Organostickstoff-Spezies an distickstoffbindende Metallzentren der VI. und VII. Gruppe. Synthese einiger Vinyliden-und Alkinyl-Komplexe des Rhenium

Zusammenfassung Die Reaktionen von Phenylacetylen und anderen Alkinen [HCCCH₂OH, HCC(CH₂)₂OH, HCCCH₂CMe₂CH₂COCH₃, HCCSiMe₃ und MeCCSiMe₃] in Gegenwart von Acetonitril oder Benzonitril mit den folgenden Komplexen wurde wie üblich bei Raumtemperatur untersucht:trans-[Mo(N₂)₂ L ₄] (L=PMePh),cis-[Mo(N₂)₂(PMePh ₂)₄],cis-[W(N₂)₂ L ₄],trans-[ReCl(N₂)L ₄],mer-[ReCl(N₂)(PPh ₃)L₃] {L=P(OMe)₃}, [ReCl₂(N₂COPh)L₃] und [(⁵-MeC₅H₄)-Mn(CO)₂(NCMe)]. Die Hauptreaktion für Phenylacetylen war stets die cyclische Trimerisierung (mit Ausnahme des Mn-Komplexes), obwohl auch Hydrogenierungsprodukte und Spezies aus einer Alkin/Nitril-Kupplung in kleineren Mengen aufgefunden wurden; für die Mo- oder W-Systeme waren die Ausbeuten unter etwa 40% relativ zum Metall, die Re-Systeme zeigten eine schwache katalytische Aktivität. Die anderen Alkine gingen (auch in niedrigen Ausbeuten) hauptsächlich Dimerisierung, cyclische oder lineare Trimerisierung neben (in noch geringerem Maßstab) Kupplungs-reaktionen mit den Nitrilen oder Hydrogenierung ein. Die Alkinylkomplexe [ReCl(CCPh)-{P(O)(OMe)₂}(PPh ₃)L₂] und [ReCl(CCPh) {P(O)(OMe)₂}(NCMe)₂ L] wurden aus der Reaktion vonmer-[ReCl(N₂)(PPh ₃)L₃] mitPhCCH sowohl in Abwesenheit als auch in Gegenwart von NCMe gebildet, wohingegen der Benzonitril/Distickstoff-Komplex [ReCl(N₂)(NCPh)L₃] entweder aus der Reaktion dieses N₂-Komplexes mit NCPh oder über die Reaktion von [ReCl₂(N₂COPh)L₃] mit NCPh in Gegenwart von NaOMe gebildet wurde. Die Vinylidenverbindungtrans-[Re(CNMe)(C=CHPh)(dppe)₂] [BF₄] (dppe=Ph ₂PCH₂CH₂PPh ₂) wurde in der Reaktion vontrans-[ReCl(CNMe)-(dppe)₂] mitPhCCH in der Gegenwart von Tl[BF₄] gebildet, wobei keine detektierbaren Mengen irgendeines von Alkin abgeleiteten organischen Produkts entstanden.

     

Hydroformylation of alkyl alkenes catalyzed by rhodium supported on MCM-41: The effect of H3PW12O40 on the catalytic activity and recycling

Heteropolyacids impregnated with rhodium(I) or (III) complexes were prepared and used as supported catalysts in the hydroformylation of alkyl alkenes. Two general types of catalysts were prepared and tested: rhodium(I) or (III) in the presence and in the absence of the heteropolyacid H₃PW₁₂O₄₀, 25H₂O (adopted as HPW₁₂) supported on MCM-41 (30 Å). 1-Octene was chosen as a model substrate. Different types of supported catalysts were tested in the hydroformylation of 1-octene and other alkyl alkenes. The effects of the temperature and the type of solvent on the reaction were studied. The results showed that the supported catalysts containing the heteropolyacid H₃PW₁₂O₄₀, 25H₂O (HPW₁₂) along with rhodium(I) or (III) gave higher catalytic activity. In addition, the recycling of the supported catalysts was studied and the results showed again the important effect of the presence of HPW₁₂ on the recycling of the rhodium catalysts.     

红外多光子解离亚磷酸三甲酯产生可见及紫外荧光的研究

近年来,科学家们为了寻找一种在可见区工作的化学激光体系,重新对一些高放热的磷化物的化学发光反应发生兴趣.对磷化物光解行为的研究表明,光解过程和产物与燃烧反应有许多相似之处.这是磷化物光解方面的初步探索.十年前,Merrow 和Nogar 曾用TEA CO_2激光对亚磷酸三乙酯P(OC_2H_5)_3进行了红外     

Direct Determination of Phosphite in Fertilizers by Flow‐Injection Amperometry

A sensor based on graphite electrode modified with palladium‐platinum‐palladium film is proposed for phosphite determination by flow‐injection amperometry. The modified electrode was prepared by a sequential cathodic deposition of Pd, Pt and Pd on a graphite electrode from 0.5% m/v PdCl₂+28% m/v NH₄OH and 2% m/v H₂PtCl₆+10% v/v H₂SO₄ solutions. After suitable conditioning, the electrode showed catalytic activity for phosphite oxidation when 0.15 V was applied. The proposed system handles approximately 50 samples per hour (0.01–0.05 mol L^?1 Na₂HPO₃; R²=0.9997), consuming ca. 70 μL of sample per determination. The limit of detection and amperometric sensibility were 5×10^?4 mol L^?1 and 1.5 mA L mol^?1, respectively. The proposed method was applied to analysis of fertilizer samples without pre‐treatment. Results are in agreement with those obtained by spectrophotometry and titrimetry at 95% confidence level and good recoveries (96–109%) of spiked samples were found. Relative standard deviation (n= 12) of a 0.01 mol L^?1 Na₂HPO₃ sample was 2%. The useful lifetime of modified electrode was around 220 determinations. For routine purposes it means that this electrode can be continuously used for 5 hours.     

在负载H3PO4的固体上3,3,4-三甲基-4-戊烯-2-酮的催化合成

3,3,4-Trimethyl-4-penten-2-one has been synthesized by the acylation of 2,3-dimethyl-2-butene with acetic anhydride in the presence of soild-supported H3PO4.By comparison of the acylation reactions of 2,3-dimethyl-2-butene with acetic anhydride over various soilds-supported H3PO4,it was found that K10 clay,silicagel,HY zeolite and HMordenite were good supports.The results obtined indicate that the soild-supported small amounts of H3PO4 possessed higher catalytic activities,For obatining a higher yield of 3,3,4-trimethyl-4-penten-2-one different supports required different modification methods.     

M3（CO）12（M=Fe,Ru,Os）的氧原子转移反应动力学

近期研究表明,M(CO)_6(M=Cr,Mo,W)与Me_3NO作用是缔合反应,Me_3NO中氧原子亲核进攻羰基碳,使其以CO_2的形式脱离金属原子,由此产生的活性中间体M(CO)_5与外来配体快速反应生成M(CO)_5L。有关金属原子簇羰基配合物的类似反应动力学研究尚未见报道。原子簇配合物可能表现出与单核配合物不同的反应性质,并且是有效的均相催化剂,进一步了解其与Me_3NO的反应性质颇有意义。本文报道在Me_3NO存在下M_3(CO)_(12)的CO取代反应(1)的研究结果(M=Fe,Ru,Os)。     

化学镀液中次磷酸根和亚磷酸根的离子色谱测定

在HPIC-AS4A分离柱上选用2.0×10~(-3)mol/L Na_2CO_3作淋洗液分离子微量HPO_3~(2-)和较高含量的H_2PO_2~-,用串联双电导检测器的不同输出范围分别同时定量。本法用于化学镀液中H_2PO_2~-和HPO_3~(2-)的测定,得到满意结果。     

Synthesis,Characterization, and Crystal Structures of a New Coordination Polymer of Manganese(II) Containing Dimethyl Phosphate

The reaction of MnCl₂ with TMP (TMP = Trimethyl phosphate) in THF (THF = tetrahydroforan), led to the coordination polymer [Mn₂(μ₃‐DMP)₂(μ‐DMP)₂]_n (1) (DMP = dimethyl phosphate). This complex was characterized by elemental analysis, IR spectroscopy and single‐crystal structure of 1 . Crystal data for 1 at ?173 °C: triclinic, space group , a = 9.7071(11), b = 10.4482(11), c = 10.6242(11) Å, α = 88.892(2)°, β = 80.829(2)°, γ = 87.572(2)°, Z = 2, R1 = 0.0441.     

二羟丙酮的气相色谱分析

用衍生气相色谱法测定了二羟丙酮的酶制法体系中二羟丙酮的含量,选用六甲基二硅胺烷（ＨＭＤＳ）、六甲基二硅胺烷加三甲基氯硅烷（ＴＭＣＳ）、Ｎ,Ｏ－双（三甲基硅烷基）乙酰胺（ＢＳＡ）为衍生试剂,并对其衍生条件进行了研究。该法的回收率为９８．３１％～１０１．３１％,ＲＳＤ为２．０２％～３．５８％。     

辅助热稳定剂对钡锌复合体系性能的影响

探讨异辛酸钡和异辛酸锌复合体系对聚氯乙烯(PVC)透明性能的影响, 以此为基础考察辅助热稳定剂水滑石(LDH)、 亚磷酸酯和β-二酮3种复合体系对PVC透明性能的影响. 结果表明, LDH能显著改善PVC的各项热稳定性能, 并且与Ba/Zn体系产生了显著的协同效应. 3种不同的辅助热稳定剂都能有效改善PVC的初期热稳定性能.