Structural, mesomorphic, photoluminescence and thermoelectric studies of mononuclear and polymeric complexes of copper(ii) with 2-hexyldecanoato and 4,4′-bipyridine ligands

Norbani Binti Abdullah, Rauzah Hashim, Lailatun Nazirah Ozair, Yasameen Al-Hakem, Habibah Samsudin, Anita Marlina, Malinda Salim, Suhana Mohd. Said, Balamurugan Subramanian, Abdul Rahman Nordin

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10 Citations (Scopus)

Abstract

[Cu(R)2(bpy)2]·2RH (1) and [Cu2(R)4(bpy)]x (2) were obtained from the reaction of [Cu2(R)4(RH)2] (R = 2-hexyldecanoato) with 4,4′-bipyridine (bpy) using different work-up procedures. Complex 1 consisted of single crystals and its molecular structure showed a distorted octahedral Cu(ii) with two chelating bidentate R. Complex 2 has a similar structure as crystals of a linear-chain coordination polymer, [Cu2(CH3(CH2)5COO)4(bpy)]x (3). Both 1 and 2 were thermally stable (Tdec = 240°C for 1; 220°C for 2), have low melting temperatures (Tm = 52.3°C for 1; Tm = 48.3°C for 2) and exhibited temperature-dependent mesomorphisms. For 1, the mesomorphism arose from the change in the binding mode of R from chelating to bridging during isotropization, while for 2, the mesomorphism arose from the breaking of the Cu-Nbpy bonds. The mesophases for 2 were cubic columnar (Cub, P4332) and rectangular columnar (ColR, space group p2gg) on cooling from 150°C, Cub and hexagonal columnar (ColH) on cooling from 184°C (isotropic liquid phase), and ColH and nematic columnar (ColN) on cooling from 190°C. These complexes also exhibited photoluminescence upon charge transfer and d-d excitation. Finally, the Seebeck coefficient value (Se) for 2 was -0.47 mV K-1, identifying it as a potential thermoelectric material.

Original languageEnglish
Pages (from-to)11036-11045
Number of pages10
JournalJournal of Materials Chemistry C
Volume3
Issue number42
DOIs
Publication statusPublished - 24 Sep 2015
Externally publishedYes

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