Supramolecular Design And Construction Based On The Structural Orientations Of Preformed Mo/Cu/S Clusters

In view of their structure diversity, their broad application prospects in industrial catalysis and optical materials, research into discrete Mo/Cu/S clusters has been so far a hot topic in both chemistry and material science. The creation of novel structural and functional extended systems by linking these prefabricated metal clusters via non-covalent interactions is, however, a newly commenced field. The low solubility of the target supramolecular assemblies, which often result in the formation of low quality single crystals, is an obstacle toward the detailed understanding of their structural characteristics and their solution-phase property investigations. This thesis is intended to tackle this problem, by increasing the solubility of the cluster precursors or introducing proper assembly strategies. A total of 39 new compounds have been synthesized and characterized, among which 22 supramolecular assemblies are formed through cluster-ligand coordination, 12 are extended systems formed by weak interactions between the cations and anions or hosts and guests, and the remaining 5 are discrete cluster compounds. They are briefly summarized as follows:1. Reactions of a linear binuclear cluster compound [Et4N]2[MoOS3(CuCN)] (1) with one or two equivalents of Cu(I) salts afforded two novel cluster-supported supramolecular complexes of {[Et4N]2[MoOS3Cu2(μ-CN)]2·2Ani}n (2) and {[Et4N]4[MoOS3Cu3CN(μ'-CN)]2(μ-CN)2}n (3), which contains the hexagonal-prismatic and double nest-shaped cluster cores, respectively. The nonlinear optical (NLO) investigations demonstrated that, by employing this synthetic strategy, the third-order NLO performances of 2 and 3 are 4.4 and 15.9 times better than those of the less NLO active cluster of 1.2. Reactions of a linear trinuclear cluster compound [Et4N]2[MoS4(CuCN)2]·H2O with two equivalents of Cu(I) salts and two equivalents of bpp afforded a novel 3D porous compound of {[MoS4Cu4(bpp)2(CN)2]·1.5(Ani)}n (4a), which bears a new topology of (42266). The aniline guests in the channels of 4a experienced an interesting stepwise guest exchange process with DMF/MeCN, leading to the formation of {[MoS4Cu4(bpp)2(CN)2]·(Ani)·(MeCN)}n (4b) and {[MoS4Cu4(bpp)2 (CN)2]·(DMF)·(MeCN)}n (4c), respectively.3. Reactions of a tetranuclear nest-shaped cluster compound [PPh4][(η5-C5Me5)MoS3(CuNCS)3]·DMF (5) with a set of bridging ligands with different lengths, flexibilities, directionalities afforded a family of cluster-based supramolecular arrays {[(η5-C5Me5)MoS3Cu3(4,4'-bipy)1.5(NCS)2]·DMF·MeCN}n (6), {[(η5-C5Me5)MoS3Cu3(bpe)1.5(NCS)2]·0.5(bpe)·2(DMF)}n (7), , {[(η5-C5Me5)MoS3Cu3(bpa)1.5(NCS)2]·0.5(bpa)·0.25(DMF)}n (8), ,{[{(η5-C5Me5)MoS3Cu3}4(μ-bpp)6(μ-NCS)4(NCS)2](NCS)2}n (9), ,{[{(η5-C5Me5)MoS3Cu3}2(NCS)3(μ-NCS)(bpa)3]·3Ani}n (10), ,[(η5-C5Me5)MoS3Cu3(1,4-pyz)(μ-NCS)2]n (11), ,{[(η5-C5Me5)MoS3Cu3(tpt)(Ani)(NCS)2]·0.75Ani·0.5H2O}n (12), ,{[(η5-C5Me5)MoS3Cu3(NCS)(μ-NCS)(H2tpyp)0.4(Cu-tpyp)0.1]·2Ani·2.5benzene}n (13) and a discrete cluster [PPh4]2[(η5-C5Me5)MoS3(CuNCS)3Cl]·2CH2Cl2 (14). The NLO properties of 5 and 10–13 were also investigated. Among them, compound 9 is the first quadruple stranded 1D compound. Besides, compound 12 and 13 are the first examples in Mo/Cu/S cluster-supported chemistry, in which the C3 and C4 symmetrical ligands are introduced.4. Reactions of a tetranuclear nest-shaped cluster compound [PPh4][(η5-C5Me5)MoS3(CuBr)3] with two flexible ligands of bpa and bpp afforded six 1D cluster-supported compounds {{[(η5-C5Me5)MoS3Cu3]2(μ-bpa)3.5Br4}·MeCN}n (16), ,{{[(η5-C5Me5)MoS3Cu3]2(μ-bpa)3Br4}·DMSO·3MeCN}n (17a), ,{{[(η5-C5Me5)MoS3Cu3]2(μ-bpa)3Br4}·2Ani·3MeCN}n (17b), ,{{[(η5-C5Me5)MoS3Cu3]2(μ-bpa)3(bpa)Br4}·0.35DMF}n (18), ,{{[(η5-C5Me5)MoS3Cu3(μ-bpa)Br2}·DMF·MeCN}n (19) and ,,,,,,,,,,,,,,,,,,,,,,,,,,,,[(η5-C5Me5)MoS3Cu3(μ-bpp)(μ-Br)Br]n (20), and their NLO properties were also investigated. Compound 16–19 are the first cluster-supported examples which were synthesized from the same two reaction components. Besides, 20 is the first triple stranded helical compound in Mo/Cu/S cluster-based supramolecular chemistry.5. Reactions of the pentanuclear cluster compound [Et4N]4[MS4Cu4I6] (M = Mo, W) with bpa afforded two analogous 1D compounds of {[MS4Cu4(bpa)2(Ani)2I2]·3.5Ani}n (M = Mo (21a), W (21b)). Additionally, self-assembly of [NH4]2[MoS4], CuBr and AgBr inα-MePy gave rise to a discrete cluster [MoS4Cu4(α-MePy)5Br2]·2(α-MePy)0.5 (22), analogous reactions without the presence of AgBr gave rise to a 1D compound {[MoS4Cu4(α-MePy)3Br](μ-Br)·(α-MePy)}n (23) and a discrete cluster compound [MoOS3Cu4(α-MePy)6Br2] (24), respectively. The NLO performances of 22 and 23 were also studied.6. Reactions of the binuclear complex of [Et4N]2[MoOS3(CuCN)] or [NH4][MOS3] (M = Mo, W) with [Cu(MeCN)4][X] (X = ClO4, BF4, PF6) and the bis-chelating ligand dmpzm gave rise to a series of cluster compounds [MoOS3Cu3(dmpzm)2CN]·H2O (25), [MoOS3Cu3(dmpzm)3][ClO4] (26), [MoOS3Cu3(dmpzm)3][BF4](27), [MoOS3Cu3(dmpzm)3][PF6](28) and [WOS3Cu3(dmpzm)3][ClO4]·3(H2O)(36b). The anion exchange reaction between 26 and C7H7SO3Na afforded [MoOS3Cu3(dmpzm)3][Tos]·0.5(H2O) (29). Treatment of 26 and 27 with aniline led to the formation of host-guest complexes [MoOS3Cu3(dmpzm)3][ClO4]·(Ani) (30) and [MoOS3Cu3 (dmpzm)3] [BF4]·(Ani) (31), respectively. Moreover, treatment of 26 with hexane, DMF and formamide and H2O gave rise to [MoOS3Cu3(dmpzm)3][ClO4]·(hexane) (33), [MoOS3Cu3(dmpzm)3][ClO4]·(DMF) (34), [MoOS3Cu3(dmpzm)3][ClO4]·(formamide) (35) and [MoOS3Cu3(dmpzm)3][ClO4]·3(H2O) (36a), respectively. Furthermore, Treatment of 36b with aniline gave rise to [WOS3Cu3(dmpzm)3][ClO4]·(Ani) (32). The NLO properties of some of these compounds were also investigated.