Details

Autor(en) / Beteiligte

• Zhang, Shu-Hua
• Zhao, Ru-Xia
• Li, Gui
• Zhang, Hai-Yang
• Zhang, Chun-Lian
• Muller, Gilles

Titel

Structural variation from heterometallic heptanuclear or heptanuclear to cubane clusters based on 2-hydroxy-3-ethoxy-benzaldehyde: effects of pH and temperature

Ist Teil von

• RSC advances, 2014-01, Vol.4 (97), p.54837-54846

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Five new Hheb complexes, HN(C 2 H 5 ) 3 ·[M 4 Na 3 (heb) 6 (μ 3 -N 3 ) 6 ], (M = Ni ( 1 ), and Co ( 2 ), [Co 4 (heb) 4 (μ 3 -OCH 3 ) 4 (μ 1 -HOCH 3 ) 4 ]·(H 2 O) 2 ( 3 ), [M 7 (heb) 6 (μ 3 -OCH 3 ) 6 ]·(ClO 4 ) 2 (M = Ni ( 4 ), and Co ( 5 ), Hheb = 2-hydroxy-3-ethoxy-benzaldehyde), were synthesized by reaction of hexahydrate perchlorate salt, Hheb, and NaN 3 under different temperature and pH conditions. Careful investigation of the effect of the reaction temperature and pH resulted in a series of compounds with different compositions and nuclearities. The diverse compounds obtained illustrate the marked sensitivity of the structural chemistry of Co- or Ni-Hheb ligand-like systems to synthesis conditions. Complexes 1 and 2 , which are heterometallic heptanuclear anion [M 4 Na 3 (heb) 6 (N 3 ) 6 ] − clusters, are formed at a pH of 5.5 and at room temperature. At a pH of 7.5 and at room temperature, a neutral molecular cubane cluster, namely 3 , is formed with a lower nuclearity. Further increase of the reaction temperature to 140 °C at the same pH resulted in formation of two heptanuclear cation [M 7 (heb) 6 (μ 3 -OCH 3 ) 6 ] 2+ clusters, 4 and 5 . The results show that the pH and reaction temperatures play a key role in the structural control of the self-assembly process. Interestingly, heterometallic heptanuclear anion [M 4 Na 3 (heb) 6 (N 3 ) 6 ] − clusters have never been reported for the family of μ 3 -N 3 − or μ 3 -O-bridged heptanuclear clusters. The magnetic properties of 1–5 were investigated and are discussed in detail.