Syntheses and Characterizations of Alkyl- and Amidotin Porphyrin Complexes:  Molecular Structure oftrans-Bis(phenylacetylido)(meso-tetra-p-tolylporphyrinato)tin(IV)

Abstract

Treatment of (TTP)SnCl 2 (TTP ) meso-tetra-p-tolylporphyrinato dianion) with an excess of lithium amides (LiNHPh, LiNPh 2 , o-C 6 H 4 (NHLi) 2 ) affords the metathesis products (TTP)Sn(NHPh) 2 (1), (TTP)Sn(NPh 2 ) 2 (2), and (TTP)Sn(o-C 6 H 4 (NH) 2 ) (3). Ligand exchanges of 1 with p-toluidine and 2,3,5,6-tetrafluoroaniline afford the complexes (TTP)Sn(p-NHC 6 H 4 Me) 2 (4) and (TTP)Sn(NHC 6 F 4 H) 2 (5), respectively. Treatment of (TTP)SnCl 2 with the bulky lithium (2,4,6-tri-tert-butylphenyl)amide or with PhNLiNLiPh does not form the corresponding amido or azobenzene complexes but produces the reduced product (TTP)Sn. In addition, the reaction of (TTP)-Sn(NHPh) 2 with PhHN-NHPh results in the production of (TTP)Sn, azobenzene, and aniline. The diethyl complex (TTP)SnEt 2 (6) can be prepared via the reaction of (TTP)SnCl 2 with 1 equiv of ZnEt 2 . The dineopentyl complex (TTP)Sn(CH 2 CMe 3 ) 2 (7) can be detected in the reaction of (TTP)SnCl 2 with neopentyllithium. The methyl derivatives cis-(TTP)SnMe 2 (8) and (TTP)SnMeBr (9) can be obtained by the treatment of (TTP)Li 2 (THF) 2 with 1 equiv of Me 2 SnBr 2 at low temperature in toluene and CH 2 Cl 2 , respectively. Treatment of (TTP)SnCl 2 with an excess of alkynyllithium salts (LiCtCPh, LiCtCSiMe 3 ) affords the metathesis products (TTP)Sn(CtCPh) 2 (10) and (TTP)Sn(CtCSiMe 3 ) 2 (11). Complexes 10 and 11 are inert at ambient temperature and are not photosensitive. Complex 10 reacts stepwise with excess MeOH cleanly to convert to (TTP)Sn(CtCPh)(OMe) (12) and then to (TTP)Sn(OMe) 2 (13) with increasing reaction time. The lability of the axial ligands in these tin porphyrin complexes correlates inversely with the basicity of the axial group. The crystal structure of 10 (monoclinic, P2 1 /c, a ) 10.9424(2) Å, b ) 14.5565(5) Å, c ) 16.4968(6) Å, R ) 90°, ) 100.7930(10) o , γ ) 90°, R 1 ) 3.53%, and wR 2 ) 8.90%) was determined from X-ray diffraction data.

Tetrakis(phenylethynyl)tin(IV)

“…The acetylenic bond distances (1.196 (7) Å in Sn1 and 1.183 (7)-1.207 (7) Å in Sn2) are consistent with a triple C≡C bond and comparable to previously reported phenylethynyl complexes, e.g. trans-[(NH 3 )Ru(C≡ CPh)(Ph 2 PCH 2 CH 2 PPH 2 ) 2 ] (1.187 (7) Å) (Touchard et al, 1997) and amidotin porphyrin (TTP)Sn(C≡CPh) 2 (1.197 (3) Å) (Chen & Woo, 1998). Therefore, despite of the short Sn-C distances, the ligands are mainly σ-bonded to the metal.…”

“…For related literature, see: Chen & Woo (1998); Dallaire et al (1993); Jousseaume et al (1998); Lahcini et al (2004); Touchard et al (1997); Kottke & Stalke (1993).…”

Building from Ga‐Porphyrins: Synthesis of Ga‐Acetylide Complexes Using Acetylenes and Polyynes

“…[14] Metal acetylides have rarely been used as axial ligands for porphyrins and never beyond the length of asingle acetylene unit (that is,m onoyne,F igure 1c). [15][16][17] These targets offer very intriguing opportunities since the acetylide ligand:1 )i s covalently bonded to the metalloporphyrin in aperpendicular orientation, 2) can be elongated to defined length through the use of conjugated polyynes,a nd 3) can be synthetically modified to allow for self-assembly reactions.F inally,w e envisioned that the resulting porphyrin-acetylide dyads could be arranged on surfaces without the loss of the acetylide ligand, offering au nique approach to hierarchical selfassembly.I ndeed, during the course of our synthetic work, apromising example established proof of concept through the placement of as imple porphyrin metal-acetylide on HOPG surface. [18] Ag eneral method for assembly of porphyrinacetylide dyads is clearly required in order to achieve the above goals.…”

Mononuclear and Mixed-Metal Dimethyltin Pacman Complexes of a Schiff-Base Pyrrole Macrocycle

“…In this complex, the trans-SnMe 2 fragment is six co-ordinate and bound in one N 4 -donor pocket in a distorted octahedral geometry, while the Zn cation is located in the opposing compartment and adopts a five co-ordinate square pyramidal geometry due to axial co-ordination of a molecule of THF, exogenous to the molecular cleft. X-ray structural data for six co-ordinate dialkyltin complexes of nitrogen based ligands are rare, 9,10 with only a few structures of dialkyltin porphyrins known, none of which contain simple alkyl ligands such as ethyl or methyl. 10 There are also only a handful of structures based on related salen-type ligands, although six co-ordinate SnMe 2 complexes have been described.…”

“…X-ray structural data for six co-ordinate dialkyltin complexes of nitrogen based ligands are rare, 9,10 with only a few structures of dialkyltin porphyrins known, none of which contain simple alkyl ligands such as ethyl or methyl. 10 There are also only a handful of structures based on related salen-type ligands, although six co-ordinate SnMe 2 complexes have been described. 11 While the Sn1-N1 bond distance at 2.153(2) Å is similar to Sn-N(pyrrole) bond distances seen in Sn IV porphyrins (ca.…”