organic radical, M is a metal or metalloid selected from antimony, arsenic, phosphorus and boron, and d is {HEAD ~ an integer} equal to from {TAIL ~ 4 6 L inclusive} 
organic radical , M is a metal or metalloid selected from antimony , arsenic , phosphorus and boron , and d is { HEAD ~ an integer } equal to from { TAIL ~ 4 6 L inclusive }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL