纤维素氧膦-钯催化有机锡试剂和酰氯偶联反应的研究

报道了采用纤维氧膦－钯络合物为催化剂,有机锡试剂与取代肉桂酰氯进行交叉偶联合成查耳酮化合物。考察了催化剂的催化性能及影响反应的因素。XPS实验结果表明,催化剂中起催化作用的是金属态钯。     

Halin图$Q$-谱半径的最大值

The Q-index of a graph G is the largest eigenvalue q(G) of its signless Laplacian matrix Q(G). In this paper, we prove that the wheel graph W_n = K_1 ∨C_(n-1)is the unique graph with maximal Q-index among all Halin graphs of order n. Also we obtain the unique graph with second maximal Q-index among all Halin graphs of order n.