集中：集中人员／to pool or gather personnel or people together; 集中精力/to channel all energy together; to 集中物力/to gather all resources together.
专心：专心读书/To concentrate on reading；专心学习/To focus on studying;专心做事/To focus on doing something;专心开会/To focus on the meeting
The two can not be used interchangeably:
The following would be wrong:(专心 can not replace 集中)
But interestingly, 集中 can be used in some phrases where 专心 is used；however, the meaning would be different.
集中读书/gathered together to study;集中学习/concentrated study on something，集中开会/to have a focused meeting (usually to solve a series of issues:集中开会解决这些问题)
So, they can not be used interchangeably.
Rule of thumb: 集中 is to gather something that can be gathered such as energy, people, buildings, etc.专心 is to concentrate on an action that will generate positive outcomes.