 
					
					
						Coordination numbers of 10 and above					
				 
				
					
						 المؤلف:  
						CATHERINE E. HOUSECROFT AND ALAN G. SHARPE
						 المؤلف:  
						CATHERINE E. HOUSECROFT AND ALAN G. SHARPE					
					
						 المصدر:  
						INORGANIC CHEMISTRY
						 المصدر:  
						INORGANIC CHEMISTRY					
					
						 الجزء والصفحة:  
						2th ed p 547
						 الجزء والصفحة:  
						2th ed p 547					
					
					
						 27-2-2017
						27-2-2017
					
					
						 1133
						1133					
				 
				
				
				
				
				
				
				
				
				
			 
			
			
				
				Coordination numbers of 10 and above
   It is always dangerous to draw conclusions on the basis of the non-existence of structure types, but, from data available at the present time, it seems that a coordination of _10 is generally confined to the f-block metal ions. Complexes containing [BH4]- and related ligands are an exception, e.g. in [Hf(BH4)4] and [Zr(MeBH3)4] the ligands are tridentate  and the metal centres are 12-coordinate. Figure 1.1 shows the structure of [Hf(BH4)4] and the cubeoctahedral arrangement of the 12 hydrogen atoms around the metal centre. The same coordination environment is found in [Zr[MeBH3)4].

Fig. 1.1 (a) The structure of [Hf(BH4)4] determined by neutron diffraction at low temperature [R.W. Broach et al. (1983) Inorg. Chem., vol. 22, p. 1081]. Colour code: Hf, red; B, blue; H, white. (b) The 12-vertex cubeoctahedral coordination sphere of the Hf(IV) centre in [Hf(BH4)4].
				
				
					
					 الاكثر قراءة في  كيمياء العناصر الانتقالية ومركباتها المعقدة
					 الاكثر قراءة في  كيمياء العناصر الانتقالية ومركباتها المعقدة					
					
				 
				
				
					
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