TY - JOUR
T1 - Synthesis, crystal structures, and dual donor luminescence sensitization in novel terbium tetracyanoplatinates
AU - Smith, Philip A.
AU - Crawford, Carlos
AU - Beedoe, Nuquie
AU - Assefa, Zerihun
AU - Sykora, Richard E.
PY - 2012/11/19
Y1 - 2012/11/19
N2 - A series of novel terbium tetracyanoplatinate compounds all incorporating tridentate 2,2':6'2″-terpyridine (terpy) or 4'-chloro-2,2':6'2″- terpyridine (terpy-Cl) were synthesized and used to investigate the phenomenon of dual-donor sensitization of Tb 3+. Judicious choice of the Tb 3+ salt and reaction conditions results in the isolation of {Tb(terpy)(H 2O) 2(NO 3)Pt(CN) 4} ·CH 3CN (1A), {Tb(terpy)(H 2O) 2(NO 3)Pt(CN) 4}·3.5H 2O (1B), {Tb(terpy-Cl)(H 2O) 2(NO 3)Pt(CN) 4}·2.5H 2O (2), [Tb(terpy)(H 2O) 2(CH 3COO) 2] 2Pt(CN) 4·4H 2O (3), or [Tb 2(terpy) 2(H 2O) 2(CH 3COO) 5] 2Pt(CN) 4·7H 2O (4). The compounds 1A, 1B, and 2 contain one-dimensional polymeric structures with bridging of [Tb(L)(NO 3)(H 2O) 2] 2+ (L = terpy or terpy-Cl) moieties by cis-bridging tetracyanoplatinate (TCP) anions as determined via single-crystal X-ray diffraction studies. Both 3 and 4, however, contain Tb 3+ coordinated by multiple acetate ligands and terpy, but not TCP, and are classified as zero-dimensional complex salts. Platinophilic interactions that dominate tetracyanoplatinate structural chemistry are present in the form of dimeric units in the polymeric compounds, but are totally absent in 3 and 4. The structural differences result in markedly different luminescence properties for the two classes of compounds. All of the polymeric compounds display efficient donor-acceptor intramolecular energy transfer (IET) from the terpy unit to the Tb 3+ ion. Although the TCP units are also directly coordinated to the Tb 3+ ion in the three polymers, only in 1B and 2 are the Pt⋯Pt interactions strong enough to provide MMLCT bands of appropriate energy to result in a dual-donor effect to the Tb 3+ sensitization. Even in these cases, TCP does not efficiently sensitize the Tb 3+, rather a broad band TCP emission results. However, terpy and acetate ligands are bonded directly to the Tb 3+ ion in 3 and 4 and provide a strong dual-donor sensitization effect as evidenced by the large QY for Tb 3+.
AB - A series of novel terbium tetracyanoplatinate compounds all incorporating tridentate 2,2':6'2″-terpyridine (terpy) or 4'-chloro-2,2':6'2″- terpyridine (terpy-Cl) were synthesized and used to investigate the phenomenon of dual-donor sensitization of Tb 3+. Judicious choice of the Tb 3+ salt and reaction conditions results in the isolation of {Tb(terpy)(H 2O) 2(NO 3)Pt(CN) 4} ·CH 3CN (1A), {Tb(terpy)(H 2O) 2(NO 3)Pt(CN) 4}·3.5H 2O (1B), {Tb(terpy-Cl)(H 2O) 2(NO 3)Pt(CN) 4}·2.5H 2O (2), [Tb(terpy)(H 2O) 2(CH 3COO) 2] 2Pt(CN) 4·4H 2O (3), or [Tb 2(terpy) 2(H 2O) 2(CH 3COO) 5] 2Pt(CN) 4·7H 2O (4). The compounds 1A, 1B, and 2 contain one-dimensional polymeric structures with bridging of [Tb(L)(NO 3)(H 2O) 2] 2+ (L = terpy or terpy-Cl) moieties by cis-bridging tetracyanoplatinate (TCP) anions as determined via single-crystal X-ray diffraction studies. Both 3 and 4, however, contain Tb 3+ coordinated by multiple acetate ligands and terpy, but not TCP, and are classified as zero-dimensional complex salts. Platinophilic interactions that dominate tetracyanoplatinate structural chemistry are present in the form of dimeric units in the polymeric compounds, but are totally absent in 3 and 4. The structural differences result in markedly different luminescence properties for the two classes of compounds. All of the polymeric compounds display efficient donor-acceptor intramolecular energy transfer (IET) from the terpy unit to the Tb 3+ ion. Although the TCP units are also directly coordinated to the Tb 3+ ion in the three polymers, only in 1B and 2 are the Pt⋯Pt interactions strong enough to provide MMLCT bands of appropriate energy to result in a dual-donor effect to the Tb 3+ sensitization. Even in these cases, TCP does not efficiently sensitize the Tb 3+, rather a broad band TCP emission results. However, terpy and acetate ligands are bonded directly to the Tb 3+ ion in 3 and 4 and provide a strong dual-donor sensitization effect as evidenced by the large QY for Tb 3+.
UR - https://www.scopus.com/pages/publications/84869483758
U2 - 10.1021/ic3013975
DO - 10.1021/ic3013975
M3 - Article
SN - 0020-1669
VL - 51
SP - 12230
EP - 12241
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 22
ER -