Selected bond lengths (Å) and angles (°) for [Co^II(TMPP)(4-CNpy)]·CHCl₃ (1), [Co^II(TClPP)(4-CNpy)] (2) and several related porphyrinic and non-porphyrinic complexes.

Complex	Porphyrin core deformation typea	M–Npb	M–XLc	M–PCd	Ref.
Co( ii ) porphyrin complexes
[CoII(TPP)]e	+++Ruf	1.923	—	0.050	48
[CoII(TPP)]e	+++Ruf	1.949	—	0.009	51
[CoII(TPP)(NO2)(Lut)]−e,f	++Ruf	1.959(2)	2.017(2)(Lut), 1.925(2) (NO2)	0.044	49
[CoII(TPP)(1-MeIm)] e,g	−Ruf	1.978(3)	2.157(3)	0.139	52
[CoII(TPP)(pip)2]e,h	Planar	1.987	2.436(2)	0.000	50
[CoII(TCPP)(py)2]i	++Ruf	1.961	1.958	0.000	53
[CoII(OEP)(DMAP)]j,k	Planar	1.981(3)	2.191(2)	0.156	54
[CoII(TPP)(pipz-S)]l	++−Sad, −Ruf	1.989(5)	2.241(5)	0.134	55
[CoII(TMPP)(4-CNpy)]·CHCl3 (1)	Ruf, +sad	1.984(3)	2.209(3)	0.1404(8)	This work
[CoII(TClPP)(4-CNpy)] (2)	++Ruf, +sad	1.977(3)	2.196(3)	0.1440(7)	This work
4-Cyanopyridine metalloporphyrins
[NiII(PFPP)(4-CNpy)2]m	Planar	2.283	2.220	—	56
[FeIII(TPP)(4-CNpy)2]e	+++Ruf, sad	1.952(4)	1.996/2.008	—	21
[FeII(TMP)(4-CNpy)2]n	Planar	1.992	1.996	—	22
[{RhIII(OEP)}2(μ2-4-CNpy)]j	Planar	2.032(4)	2.273(4)	—	22
[ZnII(TBAP)(4-CNpy)]o	+Ruf, +sad	2.060(6)	2.159(2)	—	57
4-Cyanopyridine-Co( ii ) non-porphyrinic complexes
[CoII(SO4)(4-CNpy)2(H2O)3]	—	—	2.135(1)/2.200(1)	—	58
[CoII(L1)2(4-CNpy)2]p	—	—	2.159	—	59
{[CoII(μ-Br)2(4-CNpy)2]}n	—	—	2.202	—	60

^aSee the description of different types of the porphyrin core deformation in the text, planar designate a planar porphyrin core. +: moderate, ++: important, +++: very important and “−”: weak deformation.

^bM–N_p = average equatorial distance between the center metal and the nitrogen atoms of the pyrroles.

^cM–X_L = distance between the metal atom and the coordinated atoms of the axial ligands.

^dM–P_C = distance between the metal atom and the mean plane made by the 24-atom core of the porphyrin (P_C).

^eTPP = meso-tetraphenylporphyrinato.

^fLut = 2,6-lutidine.

^g1-MeIm = 1-methylimidazole.

^hpip = piperidine.

ⁱTCPP = meso-tetra(4-carboxyphenyl)porphyrinato.

^jOEP = octaethylporphyrin.

^kDMAP = 4-(dimethylamino)pyridine.

^lpipz-S = (piperazin-1-yl)sulfonyl)naphthalen-1-amine.

^mPFPP = meso-tetra(pentafluorophenyl)porphyrinato.

ⁿTMP = meso-tetramesitylporphyrinato.

^oTPBP = meso-{tetrakis-[4-(benzoyloxy)phenyl]porphyrinato}.

^pL1 = 3,5-di-t-butylbenzosemiquinonato.