The barium complex [Ba{N(SiMe₃)₂}₂]₂ has been used to catalyse the dehydropolymerisation of the phosphine-functionalised hydrosilane 4-Ph₂P-C₆H₄SiH₃ (A) with the α,ω-diamine 1,4-(CH₂NHMe)₂-C₆H₄ (C), for the production of –[Si(4-C₆H₄PPh₂)H–N(Me)CH₂-C₆H₄-CH₂N(Me)]_n– polycarbosilazanes that contain dangling phosphino groups along the polymer backbone. The comonomers A and C, specifically prepared for this purpose and comprehensively characterised, lend themselves well to barium-promoted dehydrocoupling catalysis. They allow for the formation of linear, amine-capped polymers with molecular weights in the range 4000–8000 g mol⁻¹, as estimated by DOSY and ¹H end-group NMR analyses. The terpolymerisation of C with various mixtures of A and PhSiH₂R (R = H or Ph) led to the formation of terpolymers featuring various contents of phosphine-functionalised silazane groups, with an overall composition that reflects well the initial feed ratio of the comonomers. Thermal decomposition and flammability were studied at the microscale on a series of polycarbosilazanes to assess the effect of molecular groups on thermal stability and heat release. The SiCN backbone containing the silazane group significantly contributes to the “charring” of the polymer. By contrast, PPh₂, as other groups bearing a phosphorus atom in a low oxidation state, is not an effective char promoter.

中文翻译：

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含磷聚碳硅氮烷：通过脱氢偶联催化和阻燃性能合成


钡络合物 [Ba{N（SiMe₃）₂}₂]₂ 已用于催化膦官能化氢硅烷 4-Ph₂P-C₆H₄SiH₃ （A） 与 α，ω-二胺 1,4-（CH₂NHMe）_{2-C 6}H₄ （C），用于生产 –[Si（4-C₆H₄PPh₂）H–N（Me）CH_{2-C 6}H_{4-CH 2}N（Me）]_n– 聚碳硅氮烷，其包含沿聚合物主链悬垂的膦基团。为此专门制备并经过全面表征的共聚单体 A 和 C 非常适合钡促进的脱氢偶联催化。它们允许形成分子量在 4000–8000 g ^mol-1 范围内的线性胺封端聚合物，如 DOSY 和 ¹H 端基 NMR 分析估计的那样。C 与 A 和 PhSiH₂R（R = H 或 Ph）的各种混合物的三元共聚导致形成三元共聚物，其三元共聚物具有各种含量的膦官能化硅氮烷基团，其整体组成很好地反映了共聚单体的初始进料比。在微观尺度上研究了一系列聚碳硅氮烷的热分解和可燃性，以评估分子基团对热稳定性和热释放的影响。 含有硅氮烷基团的 SiCN 主链显着有助于聚合物的“炭化”。相比之下，PPh₂ 与其他带有低氧化态磷原子的基团一样，不是有效的 Char 促进剂。