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Title: Cyanate groups in higher oxidation state metal cluster chemistry: Mixed-valence (II/III) Mn 16 and Mn 18 clusters

Here, the employment of cyanato (OCN -) group in high oxidation state manganese cluster chemistry, in conjunction with carboxylate ions and the organic chelating/bridging ligand 2-(hydroxymethyl)pyridine (hmpH), is reported. The syntheses, crystal structures, and magnetochemical characterization are described for [Mn 16O 8(OR) 4(OCN) 4(O 2CMe) 12(hmp) 6(ROH) 2] (R = Me (1), Et (2)) and [Mn 18O 14(O 2CR) 18(hmp) 4(hmpH) 2(H 2O) 2] (R = Me (3), Et (4)). The 2:1:1:1 reactions of Mn(O 2CMe) 2·4H 2O, hmpH, NaOCN and NEt 3 in solvent MeOH or EtOH afford the isostructural complexes [Mn 16O 8(OR) 4(OCN) 4(O 2CMe) 12(hmp) 6(ROH) 2] (R = Me (1), Et (2)). The [Mn 164-O) 43-O) 4(μ-OMe) 43-OR) 6(μ-OR) 6] 10+ core of representative complex 1 comprises a Mn II 4Mn III 4 double-cubane subunit attached on either side to two symmetry-related Mn IIMn III 3 defective dicubanes. A similar reaction of Mn(O 2CR) 2·4H 2O, hmpH, NaOCN and NEt 3, but in solvent MeCN, led instead to the formation of [Mn 18O 14(O 2CR) 18(hmp) 4(hmpH) 2(H 2O) 2] (R = Me (3), Et (4)). Compounds 3 and 4 are very similar to each other and can be described as amore » central [Mn III 4(μ-O) 6] rodlike subunit attached on either side to two symmetry-related [Mn 7O 9] subunits. Variable-temperature, solid-state dc and ac magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions in all compounds, and possible S = 2 or 1 (for 1 and 2) and S = 0 (for 3 and 4) ground state spin values. The combined results demonstrate the ability of cyanato groups to facilitate the formation of new polynuclear Mn II/III complexes with structures different than these obtained from the use of the related azides.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [2] ;  [5] ;  [1]
  1. Brock Univ., St. Catharines, ON (Canada). Dept. of Chemistry
  2. Univ. of Cyprus, Nicosia (Cyprus). Dept. of Chemistry
  3. Univ. of Cyprus, Nicosia (Cyprus). Dept. of Chemistry; Univ. of Florida, Gainesville, FL (United States). Dept. of Chemistry
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
  5. Univ. of Florida, Gainesville, FL (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
AC02-05CH11231; DMR-1213030
Type:
Accepted Manuscript
Journal Name:
Polyhedron
Additional Journal Information:
Journal Volume: 108; Journal Issue: C; Related Information: © 2015 Elsevier Ltd. All rights reserved.; Journal ID: ISSN 0277-5387
Publisher:
Elsevier
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Brock Univ., St. Catharines, ON (Canada); Natural Sciences and Engineering Research Council of Canada (NSERC); European Research Area (ERA); Ontario Trillium Foundation; National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Manganese; Cyanates; 2-(Hydroxymethyl)pyridine; Crystal structures; Magnetism
OSTI Identifier:
1439196
Alternate Identifier(s):
OSTI ID: 1250199