Tetrahedron complex Linear

Figure 5 Triple tetrahedra In (a) Na Cdz[S 0 Q] and (b) Na Cd [SI O Q]. Linear anionic tetrahedron complexes In (c) tliagallolte and (d) medaite. The A, 0 tetrahedron (tiragallolte) and the V,0 tetrahedron (medaite) are dotted.

Yadav JS, Abraham S, Reddy BVS, Sabitha G (2001) Addition of pyrroles to electron deficient olefins employing InCL. Tetrahedron Lett42 8063-8065. doi 10.1016/S0040-4039(01)01697-5 Yamamoto T, Morita A, Miyazaki Y, Mamyama T, Wakayama H, Zhou ZH, Nakamura Y, Kanbara T, Sasaki S, Kubota K (1992) Preparation of Jt-conjugated poly(thiophene-2,5-diyl), poly(p-phenylene), and related polymers using zerovalent nickel complexes. Linear structure and properties of the ii-conjugated polymers. Macromolecules 25 1214-1223. doi 10.1021/ ma00030a003... 

The number k—n +bl2 is the maximal number of linearly independent 1-cycles. Depending on how one counts cycles, the actual number may differ from rHi(K) For example, consider the 1-complex determined by the vertices and edges of a tetrahedron Euler-Poincar gives rHi(R)=3, whereas some chemists may feel that there are four... 

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