貌似很多要收费的。。。目前只有这个
2003年西北大学化学系有机化学硕士研究生复试题(共3页,17道题,满分100分,可以不抄题,写清题号
1. 请叙述你参加过或正在从事的科研课题的题目、意义、成果,并随卷子寄来你发表的论文、学士论文。若应届生尚未完成学士论文的,请你的指导教师在你写的本题答案后签字。(10分)
2. 有机化合物结构测定前为什么要先做样品的纯度检验?请叙述有机化合物的纯度检验如何进行?(5分)
3. 下列两个化合物中ha和hb的化学位移哪个大?为什么?(2分)
4. 有一个化合物的分子量为116,ms中m :m+1峰丰度比为100:6.5,在c6h14no ;c6h12o2 ;c8h4o三个式子中哪个是可能的分子式?说明理由。(4分)5.在常温下,下列有*号的质子在1h-nmr中出几重峰(cdcl3溶剂)(4分)
6.某化合物的质谱部分数据如下,推测可能的分子式,写出推测过程:(5分) m/z 104 105 121 122 123 124 ri 13 1.0 89 100 7.9 0.7 7.某种农药的合成步骤如下:(5分) 产物的 1hnmr数据如下: δ1.34(d,6h); δ4.32(s,2h); δ5.8(m,1h); δ7~7.8(m,5h)请推测产物的结构,写出推测过程。
8.有一化合物分子式c7h6o,其ir光谱图如下,试推测结构,写出推测过程。 (5分)
9. 将以下段落翻译为中文(5分)the importance of carbanions in synthesis is exemplified by the grignard and wittig reactions. although they are among the most versatile and useful reactions in organic chemistry, carbanion-based reactions are generally known to be very sensitive towards air and water. the required deviation from ambient conditions along with the commonly used methods for their generation leads to several fundamental drawbacks when the principles of green chemistry are applied: (1) large volumes of anhydrous organic solvents are required which could potentially increase volatile organic emissions; (2) anhydrous conditions require excess drying agents which leads to unwanted waste; (3) anhydrous conditions also require the protection of functional groups such as hydroxy groups and carboxylic acids; (4) the requirement of inert gas atmosphere implies that the catalyst is prone to deactivation, which will increase the amounts of metal waste; (5) requirement of stoichiometric amounts of metals also leads to a large amount of metal waste; and (6) the general use of organic halides as the carbanion source will generate a stoichiometric amount of halide waste, as well as requiring multi-step synthesis of halides.
10. 减压蒸馏装置中导气毛细管有什么作用? 如不用导气毛细管, 用什么方法可以代替?该替****法除起到毛细管的作用外,还有什么优点? (5分)
11. alcl3催化苯与醋酸酐反应制备苯乙酮实验中, 随着醋酸酐的逐渐加入反应瓶内会有什么现象变化? (3分)
12. 在萃取中, 有哪些方法可以用来判断有机层是在上层或下层? (3分)13. 水蒸气蒸馏如何判断蒸馏结束? (3分)
14. 一般从库房中领到的苯甲醛其瓶中有少量白色固体,此白色固体是什么?(3分)
15. 薄层色谱中,样品rf数值如果太大或太小,如何调节?(4分)
16. 有机溶剂重结晶应采用什么样热溶解装置?对于冷却后容易析出的化合物在热过滤时如何避免损失?(4分)
17. 由指定原料合成目标物,其它试剂自选 (30分) |