Linear-Chain Structures of Platinum(II) Diimine Complexes
Abstract
The structures of three linear-chain platinum(II) diimine complexes have been determined [Pt···Pt, Å]: Pt(bpm)Cl_2·0.5(nmp) (3) [3.411(1), 3.371(1)], Pt(phen)(CN)_2 (6) [3.338(1), 3.332(1)], and Pt(bpy)(NCS)_2 (7) [3.299(2)] (bpm = 2,2'-bipyrimidine, phen = 1,10-phenanthroline, bpy = 2,2'-bipyridine, nmp = 1-methyl-2-pyrrolidinone). The Pt···Pt distances in these and in seven related compounds range from 3.24 to 3.49 Å. While we find evidence of interligand interactions influencing these structures, the Pt···Pt bonds are the most important of the stacking forces. The metal−metal distances are generally consistent with an electronic structural model in which σ-donor/π-acceptor ligands strengthen Pt···Pt bonding interactions (for example, the Pt···Pt distances in 3 are 0.04 and 0.08 Å shorter than in the bpy analogue). We have also found that the yellow form of Pt(dmbpy)(NCO)_2 (1b) (4,4'-dimethyl-2,2'-bipyridine) has a columnar structure; however, in contrast to the linear-chain form (1), which is orange, the Pt atoms are well separated (>4.9 Å). Interestingly, the yellow form is 7% denser than the orange form; this result is consistent with the concept that directed intermolecular interactions give rise to lower density polymorphs. Crystal data: (3) monoclinic, C2/m (No. 12), a = 12.668(4) Å, b = 15.618(6) Å, c = 6.704(3) Å, β = 93.43(3)°, Z = 4; (6) orthorhombic, Pbca (No. 61), a = 38.731(13) Å, b = 18.569(3) Å, c = 6.628(1) Å, Z = 16; (7) orthorhombic, Pbcm (No. 57), a = 10.349(3) Å, b = 19.927(5) Å, c = 6.572(3) Å, Z = 4; (1b) monoclinic, C2/c (No. 15), a = 17.313(4) Å, b = 12.263(3) Å, c = 14.291(4) Å, β = 114.00(2)°, Z = 8.
Additional Information
© 1997 American Chemical Society. Received October 10, 1996; Publication Date (Web): February 26, 1997. We thank L. M. Henling and V. M. Miskowski for many helpful discussions and expert technical assistance. This work was supported by the NSF.Attached Files
Supplemental Material - ic913.pdf
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Additional details
- Eprint ID
- 73673
- DOI
- 10.1021/ic961232v
- Resolver ID
- CaltechAUTHORS:20170124-142112656
- NSF
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2017-01-26Created from EPrint's datestamp field
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2021-11-11Created from EPrint's last_modified field