The quote is from Prof. Murillo who is the author of this paper. For those who don't know him well, he worked with Al Cotton and is also the co-author of "Multiple Bonds Between Metal Atoms". This paper is a short summary of some successful and unsuccessful attempts to isolate divalent metal-metal bonded early transition complexes. It is very difficult! I love the conclusion. People often give up after sometimes only one (1) attempt! First of all, I don't consider one attempt as a real attempt. There is still a good chance after a few attempts, you may get what you want. Secondly, it is also important to know WHY it is failing. You can isolate something unexpected but something much more important than your initial goal. Third, without failure, you can't learn.