What chinese leader was immensely disappointed at nixon’s trip to communist china in 1972?

Chiang Kai-shek.

Chiang Kai-shek had been the chairman of the Nationalist Government of China.  Mao Zedong's communist forces had prevailed over the Nationalist forces and the People's Republic of China was established in 1949 under Mao's leadership.  Chiang Kai-shek and the Nationalists were forced to retreat to the island of Taiwan.  For decades the United States had refused to recognize the communist government of China as legitimate, aligning with the Nationalists in Taiwan.  Chiang Kai-shek remained in office as Director General of the Nationalist Party of China until his death in 1975. 
Nixon's trip to communist China in 1972 was the beginning of a shift in US policy regarding China.